Terminology

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AM SCREENING (also called conventional screening) The traditional way of varying tone values in a screen by increasing or decreasing the dot size; the distance between the dots remains the same. The term "AM" comes from "Amplitude Modulation", meaning the size (Amplitude) of the dots is Modulated (varied) to control tone values. See by contrast "stochastic printing (FM)".

ANGSTROM A unit of length used to express very short electromagnetic wavelengths (as with UV light). An Angstrom is equal to one billionth of a meter.

ANILOX ROLLERS Rollers that meter the flow of low viscosity liquids through the press or coater. They are hard surfaced metal or ceramic rollers whose surface contains millions of very fine dimples known as cells. The anilox roller is smothered in the liquid just prior to a doctor blade scraping-off the excess. Only the liquid left in the cells is therefore passed on to the substrate. The size, number, and depth of the cells therefore regulates how much liquid is applied. The carrying capacity of anilox rollers is expressed as BCM's (Billion Cubic Microns).

ANSI (American National Standards Institute).

ANTIOXIDANTS Used in printing ink to inhibit oxidation drying in order to delay skin from forming on the surface of the ink. A carefully balanced drier and antioxidant combination can delay skinning for several hours with little effect to drying on paper.

AQUEOUS COATING A water based alternative to varnish for protecting and enhancing print. May be applied in-line (on press) as a gloss, satin, or dull coating. Typically fast drying durable and non-yellowing.

AQUEOUS PRIMER A water based primer coat designed to seal and protect ink while also accepting other finishing enhancements like UV coating, Foil Stamp, glue, etc.

ASTM (American Society for Testing Materials) An organization that establishes voluntary standards for materials, systems, products, and services. ASTM standards give industry a common language and common yardstick for making meaningful comparisons and evaluations.

BACK-TRAPPING When wet-trapping one ink over another, back-trapping is when ink on the paper is being lifted-off by a succeeding print unit. Back-trapping results in grainy or splotchy looking solids and sometimes leads to contamination (discoloration) of the ink in the fountain. In four color process printing, back-trapping is usually characterized by low trap numbers (<50). Reducing the tack of the succeeding ink(s), or reversing their print sequence, might correct the problem; but occasionally a more involved solution is called for. Contact Graphic Ink for assistance. 

BACKING-AWAY (in the fountain) A condition in which an ink lacking flow will not stay in contact with the fountain roller so that the fountain roller can transfer ink to the ductor roller. Contact Graphic Ink Company for suggestions on how to overcome backing away in the fountain. See also "thixotropy" and "yield value".

BCM (billion cubic microns) BCM's express the carrying capacity of anilox rollers. BCM's are based on a one square inch surface area of the roller.

BLANKET In offset printing, the blanket is a fabric backed rubber sheet that wraps around the "blanket cylinder" on the printing press. The blanket is what actually transfers the ink (image) from the plate to the paper. Blankets come in a variety of gauges, plies, compressions, and compounds, and are changed periodically as they wear.

BLEED A term used to describe a printed area of the sheet that will extend beyond where the sheet trims-off.

BLEEDING A process where certain pigments such as Rhodamine or Triphenylmethane Toners like Alkali Blue or Methyl Violet may "spread" or "run" on contact with certain soaps, chemicals, or solvents. Aqueous and UV coatings can cause some ink colors to bleed or "burn-out". Sometimes the color fades-out or disappears all together. See also "color burn-out".

BLINDING (plate blinding) Loss of ink-receptivity in the plates' image areas. Plate blinding can result from a defective plate, improper exposure, or bad plate processing; but more often blinding is the result of calcium buildup in the image area of the plate, causing it to accept water and not ink. Calcium comes primarily from paper, but can also originate from tap water, old or contaminated fountain solution, or on rare occasions from ink. A good calcium washup is recommended along with new plates, fresh fountain solution (from RO or DI water if possible), and a small add of Complexing Solution to fight calcium from paper or ink. See also "calcium wash", "Complexing Solution", and "buffers".

BLISTERPACK A packaging process using heat and pressure to fuse a pre-formed plastic shape to a base substrate (usually a printed & coated paperboard platform), encasing a product inside. Special inks, board, and coating are generally involved. See also "skin packaging" and "clamshell".

BLOCKING See "set-off".

BLOOMING Material migrating to the surface of an ink film, or of an aqueous or UV coating film. Exudation is the term usually used in reference to solid materials.

BODY Where ink is concerned, body refers to how thick, or how fluid, the ink is.

BRC (Bio-derived Renewable Content) Referring to the materials derived from natural "renewable" resources such as trees, seeds, nuts, etc.

BRIX TEST (sugar test) Pronounced "bree", this test uses light refraction to monitor the deviation of a mixture from some baseline like pure water. Used mostly in the beer and wine industries for measuring sugar content as a predictor of the potential for alcohol. "Conductivity" is the preferred meathod for testing fountain solution concentration however.

BUFFERS Buffers are chemical additives for moderating pH, as with buffered fountain solution or buffered inks.

BUILDUP (on the metering roller) See "Feedback"

BURNISHING When a surface has been scuffed or rubbed, resulting in an objectionable blemish in an otherwise uniform finish. Sometimes burnishing can be prevented using specially formulated coatings or varnishes. Contact Graphic Ink for assistance. See also "scuffing".

BURNOUT See "color burnout".

BUSINESS FORMS INKS Inks formulated to run on high speed narrow web presses. Usually printing roll-to-roll rather than by the sheet. These inks often do not contain driers.

C1S (Coated 1-Side) A term used to denote paper or paper board that is clay coated on one side and not the other.

CAKING See "piling".

CALCIUM WASH  A procedure for washing the rollers in a lithographic press to remove the calcium buildup that comes from paper, ink, or fountain solution. The procedure generally involves a thorough washing of the rollers with a warm acidic water solution (vinegar & water), followed by a thorough water rinse. Special roller cleaning compounds are also available for removing calcium; available from Graphic Ink Co. See also "Complexing Solution".

CAST & CURE A way of embossing the surface of UV coating or varnish so it refracts light in a rainbow like appearance, or creates patterns or texture. Cast & Cure can be done in-line on a UV press with the addition of a special apparatus. A Nano-embossed film is pressed against wet UV varnish as it's curred. This transfers the embossed effect onto the coatings surface. The special film web is being spooled-up and can be reused. Contact Graphic Ink for more information.

CAST COATED STOCK A high-gloss enamel coated paper created by squeezing the paper between polished chrome rolls under high heat and pressure. Cast coated papers tend to be quite absorbent.

CCN (Clay Coated News) A board stock constructed of a newsprint base sheet material with a white clay surface coating to improve printability. Usually contains a significant amount of recycled fiber.

CERTIFICATE of ANALYSIS A document detailing the results of testing performed on a substance like printing ink. Normally the COA is provided to demonstrate the degree of compliance of a production lot to a known standard.

CHALKING A condition where ink is printed and dry, but still rubs-off the sheet like chalk. Chalking can result from a number of things, but essentially there doesn't remain enough ink vehicle (binder) on the surface to anchor and hold the ink pigment to the sheet. Often, applying an aqueous coating or overprint varnish will salvage the job. Contact our technical service department for assistance with chalking. See also "scuffing" and "burnishing".

CHINAWOOD OIL See "tung oil".

CHROMA The "saturation purity" of a color, as from clean and bright to gray or neutral.

CIE (commission international de l'Eclairage) Established in 1931 and based in Vienna, Austria, the International Commission on Illumination (usually known as the CIE for its French name Commission Internationale de l'Eclairage) is the international authority on light, illumination, color, and color spaces.

CIE (L *a*b*) When a color is expressed in CIE L*a*b, L* defines lightness, a* denotes the red/green value, and b* the yellow/blue value.

CIE (L*C*h) When a color is expressed in CIE L*C*h, L* defines lightness, C* specifies chroma, and h denotes hue angle, an angular measurement in color space.

CLAIMS (damage claims) Damage claims are classified as “justifiable” or “questionable” based on the role of each party in creating the damages. It’s generally recognized that it’s the buyer’s responsibility to provide the vender with all the information he needs to make the appropriate products or recommendations. Furthermore, each party along the value-added chain assumes responsibility for minimizing losses by checking for defects and taking immediate preventive actions when called for. Claims of defective product aren’t considered valid unless provable, and the failure of a printer to catch printing defects is not the responsibility of the ink maker. More complex disputes can usually be settled amicably through arbitration. See also: “guarantees”, “liability”, and “warranties”.

CLAMSHELL A packaging method similar to "blisterpack" except a tough pre-formed rigid plastic shape is "attached" to (or around) a printed paperboard graphic, encasing a product inside. See also "blisterpack" and "skin packaging".

CMS (color management system) A way of controlling color uniformity across input and output devices.

CMYK Refers to the four colors: Cyan, Magenta, Yellow, and Black, which are the primary colors used in four color process printing. Various combinations of these four colors laid down on paper as tiny dots can create the illusion of a nearly endless variety of colors. See also " stochastic printing", "AM screening", and "rosette".

COA (certificate of analysis) A document detailing the results of testing performed on a substance like printing ink. Normally the COA is provided to demonstrate the degree of compliance of a production lot to a known standard.

COATED PAPER Paper with a clay surface coating on one or both sides to enhance printability or appearance. Coated papers are available in a variety of gloss, satin, dull, or matte finishes.

COF (coefficient of friction) A measurement of the amount of "slip" between two surfaces placed face-to-face. Usually expressed as two numbers: (1) The amount of force required to get slippage to occur; and (2) the amount of force required to maintain slippage. Typically expressed in "grams" of force. COF is a consideration in selecting the appropriate coating in some printing situations. See also: "slide angle"

COLD FOIL An alternative to hot foil stamping that can be done in-line on a web or sheetfed press. Two print units and a special apparatus are required. The first print unit applies a spot adhesive to the substrate through the normal lithographic process (with the adhesive essentially acting as an ink). In the 2nd print unit a foil film is fed between the blanket and impression cylinders, pressing the foil to the substrate where it sticks to the adhesive areas. The spent film is re-spooled on a take-up roll. The process takes place at normal press speeds. Other print units can print color over the foil to achieve a wide range metallic shades and patterns. Coatings can add protection or other effects.

COLDSET INKS Usually refers to ink designed for thin, low-grade stocks like newsprint, where absorption is the primary means of drying. Typically involves a web printing process. Sometimes the term refers to solid inks that are melted and applied to the paper hot, after which chill rollers set the ink back to a solid on the paper.

COLOR BAR A narrow strip of color patches, patterns, and tints, placed at the trailing edge of a press sheet as a way to monitor the print behavior of the ink colors individually and in certain combinations. The color bar is also useful for exposing some kinds of press problems, or problems with adjustments.

COLOR BURNOUT (burnout) An objectionable color shift caused by aqueous or UV coating acting chemically on certain kinds of pigments such as alkali blue, rhodamine red, methyl violet, red lake C, and others. Special "bleedfree" pigments can usually be substituted to produce an acceptable match without the risk of burnout, but typically at higher cost.

COLOR GAMUT See "Gamut"

COLOR SPECTRUM Normally refers to that range of electromagnetic wavelengths that are visible to the human eye (as seen in nature's rainbow). The color spectrum starts at about 390 Nanometers on one end (violet), and ends at about 700 Nanometers on the other end (red). Every visible color exists between those two wavelengths, either as individual wavelengths or combinations thereof. See also "Gamut" and "Spectrophotometer".

COMPLEXING SOLUTION A fountain solution additive that offsets the negative effects of calcium buildup in the dampening system (stripes, blinding, roller stripping, toning, Etc.). Complexing Solution is a chemical water softener that bonds with calcium ions, preventing them from bonding to litho plates, rollers, or other system components. Complexing Solution isn't a substitute for good roller and dampening system maintenance, but it can buy you some time. A product of Graphic Ink Co. See also "calcium wash".

CONCENTRIC SCREENING A screen similar to AM screening except each dot is a circle within a circle, something like a bulls eye target. Concentric screens tend to use less ink and produce slightly brighter tones. Contact Graphic Ink for more information about concentric screening.

CONDUCTIVITY Refers to the ability of a substance like water to conduct electricity. Measured in micromhos, conductivity increases with the amount of electrolytes (dissolved solids) in the water, which makes conductivity a great way to dose and monitor fountain solutions. Pure distilled water is non-conductive (0 micromhos), while tap water can range from 100 to as high as 1500 micromhos in some places. See also "micromhos" & "RO water".

CONEG (Coalition of Northeastern Governors) Loosely defined as a group of Governors who enacted certain regulatory measures across multiple health, safety or environmental issues; particularly leads and other heavy metals in packaging.

CONVENTIONAL SCREENING (also called AM screening) The traditional way of varying tone values in a screen by increasing or decreasing the dot size; the distance between the dots remains the same. The term "AM" comes from "Amplitude Modulation", meaning the size (Amplitude) of the dots is Modulated (varied) to control tone values. See by contrast "stochastic printing (FM)", and also "concentric screening".

CORONA TREATMENT A process for treating plastics and other non-absorbent substrates to improve adhesion and printability. A high frequency electrical discharge is fired onto the substrate to increase its surface functionality (and dyne level), making it more receptive to inks, paints, glues, and coatings. Such substrates can usually be ordered "pre-treated" from the manufacturer or supplier, but Corona Treatment dissipates over time and in some cases may require re-treatment before printing. Our technical department can test your substrate to determine if it is sufficient for litho printing. See also: "Plastics","Reticulation", "Dyne", and "Surface Tension".

CROP MARKS Cross shaped marks placed on the edges of a press sheet (usually in the corners), to indicate where to trim the sheet.

CROSS-LINKER A press-side additive for aqueous coatings that causes the coating to harden faster and dry harder. Great for two-sided coating work. Cross-Linker should be added just prior to using the coating because the adjusted coating will not store well. Do not add cross-linker to UV coatings. Cross-Linker is available from Graphic Ink Co.

CRYSTALLIZATION When an ink containing wax dries so hard over time that its surface will not accept dry trapping or imprinting. Inks may not dry or adhere to such a surface and "reticulation" may occur.

CT (continuous tone) An image involving a range of tone values (as in a photograph), as opposed to solids on white (as with plain text on paper).

CTI (critical toning index) The treshold at which a waterless litho plate begins to carry ink in the non-image area. The higher the CTI, the less likely that toning will occur. See also "toning".

CTP (computer-to-plate) The process of imaging a litho plate directly from a digital computer file using a "plate setter" device, as opposed to using film and a vacuum table.

DEBOSSING A process of creating a three-dimensional image or design on paper or other ductile material by applying heat and pressure to the substrate using a three-dimensional die. Debossing is an indentation of the substrate as opposed to the raised image characteristic of embossing.

DELAMINATION The complete or partial separation of the layers of a laminate; such as the separation of paper coating from the base sheet.

DELTA E (ΔE) A term used in color science to express the amount of difference between two colors. "Δ" is the Greek letter used to denote "difference" (usually expressed as the triangle shaped character "Δ"), and "E" is German for "sensation". ΔE is a single numerical value that essentially averages the difference between two colors. ΔE expresses how far apart two colors are, but not where they are in color space. ΔL*, Δa*, and Δb* are the individual differences for each of the three aspects of color in the L*a*b* color space. ΔL*, ΔC*, and Δh* are the individual differences for each of the three aspects of color in the L*C*h* color space. Overall  ΔE L*a*b* is calculated by taking the square root of (ΔL²+Δa²+Δb²). Overall ΔE for L*C*h* colorspace is calculated in the same fashion, and ΔE/ab by taking the square root of (Δa²+Δb²). See also "L*a*b*", and "L*C*h*".

DENSITOMETER (reflection densitometer) A device used to read the color density of process colors on a press sheet. The device actually reads the degree of darkness on a reflected surface, but by incorporating special filters, densities of process colors can be read individually. Some densitometers also calculate dot gain (TVI) by comparing a solid patch to patches of known screen values. In a similar way, print contrast can be calculated. Densitometers are a poor color control tool for non-process colors like Pantone blends or custom colors, as the instrument is only looking for cyan, magenta, yellow, or black. See also "density" and "spectrophotometer".

DENSITY (ink density) Refers to how strong the color is on the sheet. Sometimes density is assumed to be the film thickness of the ink on the paper, which is not always the case. Density readings will rise and fall with the ink film thickness of a given ink; however, an ink with more color strength will give a higher density reading than a weak ink at the same film thickness. See also "densitometer" and "dryback".

DESENSITIZING INK Chemically enhanced transparent ink that prevents print development on carbonless papers wherever applied.

DI WATER (Deionized Water) A physical process of removing mineral ions from water using special ion-exchange resins and filtration to yield a near zero conductivity similar to distilled water. See also "conductivity", "TDS" and "RO water".

DIC COLORGUIDE A color guide, and color specification system, used in Japan but rarely in the US or Europe. DIC is for Dainippon Ink & Chemical.

DOT GAIN(TVI) The reflection halftone percentage measured on a printed sample minus the original half tone percentage file value that produced it. Essentially "dot spread".

DOUBLING A mechanical problem on the press that causes a double image, slightly offset from the original image, which usually shows-up in type or halftone dots. Doubling is an indication that the blanket is not lining-up with the plate precisely with every revolution. Improper blanket touque is a common cause, but doubling can also indicate a more serious mechanical problem with the press.

DPI (dots per inch) A measurement used to define the fineness of resolution of a printing device such as an image setter or laser printer.

DRIER In printing ink, driers trigger oxidation drying. Cobalt and manganese are the most common driers used. Grapho drier is a press side additive drier that is activated by moisture from the dampening system.

DRY COLOR Pigment (color) in its dehydrated, powdered form.

DRYBACK Any change in density, finish, or color, of an ink film as it dries.

DRYOGRAPHY A waterless lithographic printing method involving special waterless plates and inks, and chilled ink rollers. See also "waterless inks".

DUOTONE A technique for enhncing the tones of a black and white image by adding a second color to the halftone.

DUPLICATOR INKS Inks formulated to run on small offset presses that don't utilize re-circulating systems for the fountain solution, and have minimal ink and water rollers. These inks are usually of the non-skinning type to allow them to remain on the press overnight.

DUROMETER An instrument for measuring the hardness of rubber or other viscoelastic materials. Often the term "durometer" refers not to the instrument, but to the reading produced by the instrument. The durometer hardness for press rollers is typically between 45 and 60 on durometer scale (A) which goes from 0 to 100. Roller hardness is a crucial consideration in offset printing as it has a significant effect on print quality and press performance. 

DYNE  A unit of measure for the surface tension of a liquid, or surface energy of a solid surface, which helps predict how the liquid will behave on the solid surface. See also "surface tension", "reticulation", and "corona treatment".

EMBOSSING A process of creating a three-dimensional raised image or design in paper and other ductile materials, by applying heat and pressure to the substrate with a three-dimensional die. See also "debossing".

EMULSIFICATION In lithography, a condition resulting from the distribution of fountain solution in the ink. Improper emulsification will produce drying problems and poor printing.

EPDM (ethylene propylene diene monomer) A synthetic rubber compound with very good chemical, heat, ozone, and weather resistance properties. EPDM is the rubber compound recommended for press rollers used in UV printing. 

EWRA (european water resources association) Established for enhancing international cooperation in the exchange and application of scientific knowledge with respect to developing and protecting water resources. 

FADING A change of color or color strength on exposure to light, heat or other influences.

FALLING ROD VISCOMETER See "Laray viscometer".

FDA INKS Inks manufactured to be compliant with FDA standards for direct or in-direct contact with food products.

FDS (fountain drier stimulater) A fountain solution additive containing drier that acts on the ink to help it dry. Usually used in situations where excessive dampening solution is slowing the ink.

FEEDBACK In Lithographic printing, Feedback refers to ink feeding-back into the dampening sytem. Ink can buildup on the water metering rollers, or can buildup in the chill tanks. Feedback is more common in systems with "reverse-nip" water metering rollers. Properly set rollers, and carefully selected fountain solution, are essential to preventing Feedback. Graphic Ink has fountain solutions designed for reverse-nip systems.

FELT FINISH Refering generally to a soft uncoated paper surface created in the paper manufacturing process when woven felt belts squeeze a felt-like pattern into the newly formed paper.

FELT SIDE  Refers to the side of paper that was opposite the wire side in the paper manufacturing process. See also "wire side", and "felt finish".

FLAXSEED OIL (also known as linseed oil) A vegetable oil derivative of the seeds of the flax plant. Flaxseed oil is common in most oilbased sheetfed litho inks today, usually in combination with other vegetable oils. Flaxseed oil content varies depending on performance requirements such as setting speed, drying time, and hardness. Flaxseed oil dries faster and harder than soybean oil.

FLEXO A high speed printing process using fast drying liquid inks based on water, solvent, or UV chemistry. The presses are web-fed and involve a flexible rubber printing plate with a raised image, wrapped around a print cylinder. A popular printing method for labels, bags, tissues, and place mats. Flexo inks are availble from Graphic Ink Company.

FLOCCULATION The aggregation of pigment particles in the ink to form clusters or chains of "flocks". Though somewhat rare, flocculation can result in a loss of transfer, gloss, and color strength, as well as a shift in the hue of the printed ink. Proper grinding (milling) of the ink during manufacturing should prevent flocculation.

FLOCKING A print finishing process that gives printed areas a "fuzzy" feel similar to velvet.

FLOW Refers to how "liquid" an ink is, or how quickly it moves in response to gravity or other force applied. 

FLUORESCENT INKS Inks that exhibit "fluorescence", resulting in extremely bright "neon-like" colors. Fluorescent colors are sometimes double-bumped to achieve maximum brightness. Fluorescent colors are susceptible to fading when exposed to sunlight.

FLUSH COLOR A concentrated clay-like form of pigment paste that has been passed directly from its original aqueous phase as presscake, to its final oilbase phase as flush color, without ever becoming dry. Not having to re-wet dry pigment reduces the milling time required to disperse the pigment (see "ink mills"), saving energy and avoiding heat damage to the pigment.

FLUX CAPACITOR What makes time travel possible. Power requirement is 1.21 gigawatts. See also "gigawatt".

FLYING See "misting".

FM SCREENING See "stochastic printing".

FOIL STAMPING (hot foil) A special kind of off-line printing process where heat and pressure fuse an adhesive metallic foil to a substrate, creating different shiny metallic or opaque color graphics. See also alternatives "Cold Foil" and "VMP".

FRAMING (picture framing) The accumulation of slitter or coating dust on the blanket, outlining the edge of the sheet. ALSO, the accumulation of ink on the blanket outside the paper contact area. This condition is usually "tinting" that may not have shown-up on the paper yet. Framing typically relates to fountain solution. Call Graphic Ink Company for trouble shooting assistance.

FSC (forest stewardship council) Created to coordinate the development of forest management standards throughout the different bio geographic regions of the US. Contact Graphic Ink for more information, or go to our link to FSC on this website under "Resources".

G7 (GRACoL G7) An IDEAlliance proof-to-press calibration process based on principles of digital imaging, spectrophotometry, and computer-to-plate (CtP) technologies. G7 uses Gray-scale (G) and (7) solid color measurements, hence "G7", to control color throughout the process. The seven solid colors are the customary C,M,Y,K, plus the secondary colors R,G,B, which represent the "trap" colors on a press sheet. G7 utilizes existing ISO standard 12647-2 as the basis for beginning G7 calibration, and ISO 2846-1 compliant inks. Printers can become G7 qualified by going through the calibration steps from proofing to printing. Graphic Ink Company offers several ISO 2846-1 compliant inks for G7 calibration, as well as G7 consulting & qualifying service. Contact Graphic Ink for more information on G7, and see our link to GRACoL and IDEAlliance on this website under "Resources". See also "ISO 12647-2" and "ISO 2846-1".

GAMUT Usually refers to the "breadth" of color shades that are possible in a given medium like ink, printing, paint, video monitors, Etc. Graphic Ink makes a special "wide gamut" process ink that prints beyond the traditional four color process gamut.

GAS GHOSTING Also called "gloss ghosting", results from uneven drying triggered by the drying action of ink or varnish on an adjacent sheet. Gases released by ink during the drying process can migrate to an adjacent sheet and effect the drying rate of ink on that sheet. This non-uniform drying rate can lead to a faint image (ghost) being transferred from the one sheet to the other. A lot of factors come together to make a gas ghost, but the risk can be minimized by allowing the first side of the sheet to thoroughly dry before printing the other side, and by printing first the side most likely to show a ghost image (like large solids). Once occurring, a gas ghost can be difficult or impossible to eliminate. See also "ghosting".

GATF(Graphic Arts Technical Foundation) Now called "PIA" (Printing Industries of America).

GCR (gray component replacement) Using black to replace gray tones otherwise produced by combinations of cyan, magenta, and yellow.

GHOSTING The presence of a faint image of a design in areas that are not intended to receive that image. Some kinds of ghosting exhibit an image in the "gloss" of the printed finish (gloss ghosting), this results from uneven drying triggered by the drying action of ink or varnish on an adjacent sheet. Other ghosts may exhibit bands or patterns of varying ink density (mechanical ghosting). Call the ghostbusters at Graphic Ink for the best trouble-shooting assistance available. See also "gas ghosting".

GID INKS (glow-in-dark) Inks that glow in the dark. Best results are achieved by silkscreen printing. In offset inks, several layers of ink are generally required to produce acceptable results.

GIGAWATT A measure of electrical power equaling one billion watts. See also "flux capacitor".

GLOSS GHOSTING (see "gas ghosting" and "ghosting")

GOE (Pantone Goe system) A Pantone color selecting system released in 2007 consisting of 2058 colors divided into 165 color families. RGB values are displayed with the ink formulas in the color deck. Contact Graphic Ink for more information.

GRACoL Stands for General Requirements for Applications in Commercial offset Lithography, a comprehensive set of guidelines for planning and processing work for printers. See our link to GRACoL on this website under "Resources".

GRAFO DRIER An old ink additive (drier) that was triggered by moisture from the dampening system. No longer available in the US. See alternative: "Graphico Drier".

GRAIN (paper grain) The direction in which most of the fibers in a paper are running. Most of the fibers in paper tend to run in the same direction that the paper moves through the paper making machine. The grain direction should run through the press the same way, with the grain running in the same direction as the sheet through the press.

GRAPHICO DRIER A water activated drier for lithographic paste inks. Available from Graphic Ink Company.

GRAY BALANCE When the proper combination of cyan, magenta, and yellow dots come together to produce a neutal gray. Used as a quality control measure for achieving proper color balance.

GRIPPER EDGE This is the leading edge of the sheet as it passes through the offset press. Gripper fingers on the press grab this edge of the sheet to hold and direct it as it moves through the press.

GUARANTEES Ink makers are typically short on guarantees because of numerous circumstances in printing that are outside the ink maker’s control. Ink buyers should be very clear about their expectations when ordering, and any guarantees offered should be specific and in writing. Many disputes regarding ink result from false assumptions being made. See also: “claims”, “liability”, and “warranties”.

H-UV H-UV refers to a specially matched UV ink and UV drying system. The ink is highly reactive to a reduced range of the UV spectrum, which corresponds to what the specially doped H-UV bulb produces. The result is less energy consumption (only one lamp at the end of the press), less heat generation, and no ozone emitions (elliminating the need for ventilation). Graphic Ink Company has both H-UV and LED-UV sheetfed inks available.

HACCP (hazard analysis & critical control points) A preventive approach to food safety (a written food safety plan) that helps elliminate hazards to the food chain from food production to processing, preparation, packaging, distribution, and consumption. See also "SSOP".

HALFTONE An image of varying tone values created by varying the size or number of tiny dots of ink. Usually refers to a single color image involving black ink.

HAPs (hazardous air pollutants) In general a list of 189 chemicals and chemical categories that are listed as hazardous air pollutants or HAPs.

HAZING A term sometimes used to describe "toning", a condition where ink is adhering to the plates non-image area. Often relating to waterless litho printing. Contact Graphic Ink for assistance. See also "toning".

HEATSET INKS Inks that dry by evaporation when the paper passes through an oven at high speed followed by chill-rollers that "set" the ink hard. Heatset printing is almost always a web printing process.

HEXACHROME A six color printing process using cleaner inks with higher fluorescence and the addition of Orange and Green, which expands the printable color saturation and color ranges possible.

HICKEYS Tiny white specs or spots in the printed area caused by particles stuck to the plate or blanket. Hickeys usually exhibit a doughnut-like shape.

HMIS (Hazardous Materials Identification System) A four part numerical rating system for communicating basic hazard information about a chemical or substance. Health, Flammability, and Physical hazard, are rated from 0 to 4, with 4 being "severe hazard". The last section is for "personal protection" recommendations, if any. A products HMIS rating is typically displayed on the product label.

HUE The shade of a color as from red to green, yellow to blue, Etc.

HYBRID INKS (UV Hybrid) Special litho inks that can be UV coated in-line due to their partial UV chemistry. These inks require UV drying prior to, and after, applying the UV coating. Special washes are involved, but UV Hybrid inks are generally quite compatible with conventional blankets and press rollers. Contact Graphic Ink for UV Hybrid inks.

IDEAlliance (International Digital Enterprise Alliance) A membership organization dedicated to advancing core technologies, practices, and communication, to facilitate the creation, production, management, and delivery, of knowledge-based media content, digitally and in print. See our link to IDEAlliance on this website under "Resources".

IMPRINT A pass through the press to add some kind of variable information (usually in black) to a previously printed master. An example would be printing different names and titles on a common master business card.

IN-LINE Refers to a print finishing process performed at the same time as the printing process, at the end of the press. See by contrast: "off-line"

INK MILL A devise that "grinds" ink into a uniformly smooth body and texture. Because paste inks are a combination of liquids and solids, this grinding process is performed to insure complete dispersion of the solids into the liquid (vehicle). Three roll mills "sheer" the ink under high pressure between cooled steel rolls, while a doctor blade removes the finished ink at the end. Shot mills pump the ink into a cooled chamber filled with grinding media (steel or ceramic beads), while special discs rotate within the chamber. The ink is forced through the moving grinding media, and through a filter screen at the end which contains the media but allows the ink to pass.

INK OPTIMIZING SOFTWARE See "Optimizing software".

INKOMETER A laboratory instrument for reading the tack of inks under controlled conditions. The instrument involves three rotating rollers that simulate conditions on an offset press. Temperature, film thickness, surface area, and splitting force (speed) is all controlled. See also "tack".

INTEGRATED DAMPENING The murging of the ink and dampening systems prior to inking the plate. A "bridge roller" is used to murge the ink and water, and can be engaged or disengaged on many press models. Non-integrated dampening is referred to as "conventional dampening".

INTERFERENCE PIGMENTS These special pigments create inks and coatings that exhibit iridescent effects, or that shift color according to the angle of viewing. Also available in various metallic, sparkle, and pearlescent effects.

IRIDESCENCE A lustrous rainbow-like color effect that changes according to the angle of viewing. See also "interference pigments".

ISO (International Standardization Organization) The worlds largest developer and publisher of international standards. Companies can be ISO certified by meeting and maintaining the requirements outlined by the organization for defining, monitoring, and documenting, processes and performance.

ISO 12647-2 This standard put out by ISO relates to actual offset printing and press sheets. The standard defines acceptable print performance on a variety of substrates, and among other things, forms the basis for G7 calibration on the press.

ISO 2846-1 This is a standard put out by ISO for sheetfed litho inks. The standard sets bouderies on the shade and opacity of four color process inks within a defined ink film thickness range. The standard does not apply to actual press sheets, but to proofs produced in the laboratory on a specific wood free standard substrate. Graphic Ink Company manufactures several process inks that comply with this ISO standard.

JOULE A derived unit of energy expressing the amount of energy despensed in moving a specified mass, heat, or electrical current, through a specified resistance. The joule (or millijoule) is the usual unit of measure for defining the total quantity of UV energy that ink and paper are exposed to in UV printing.

JUST-WATER INKS These special litho inks can be run with plain water as opposed to chemically enhanced water (fountain solution).

K&N ABSORPTION TEST A test that reveals the surface absorption characteristics of paper. The test involves applying a thick film of special ink to the substrate and waiting for dies in the ink to soak into the paper surface. When the ink is later wiped-off, the stain left behind reveals how much absoption took place, and how uniform the paper surface is. Sections of the ink can be wiped-off at different times, and the stains read by a densitometer, to better understand the "rate" of absorption. The Graphic Ink Lab can perform the K&N absorption test.

KAIZEN A Japanese term meaning "good change". Keizen is a philosophy of continual improvement that puts the emphasis on getting everyone involved in the process. See also "PDCA".

KNOCK-OUT An area that is reversed-out from printing to allow another color (or colors) underneath to show through, or another color to be dropped-into that location, or even just to let the unprinted paper show through the knock-out area. See also "reverse".

L*a*b* (CIELAB) When a color is expressed in CIE L*a*b* color space, L* defines lightness, a* denotes the red/green position on a grid, and b* the yellow/blue position on the grid. See also "Delta E".

L*C*h (CIELCH) When a color is expressed in CIE L*C*h color space, L* defines lightness, C* specifies chroma, and h denotes hue angle, (an angular measurement in color space). See also "Delta E".

LAMINATING A process of bonding together two or more layers of material's, usually using heat and pressure, and an adhesive layer. In printing, lamination usually referes to a clear plastic film being fused over the top of a printed sheet to enhance appearance or durability. Special inks may be required, please contact Graphic Ink for more information.

LARAY VISCOMETER A laboratory instrument for measuring the viscosity and yield value of paste inks and other high viscosity materials. Sometimes referred to as a "falling rod viscometer", the Laray involves a weighted rod that passes vertically through a precisely matched orifice covered with the test material. The time required for the rod to move a specified distance through the test material helps determine the viscosity & yield value of the material. Various weights can be added to the rod, and multiple drop times can be factored for better characterization of the material being tested.

LASER RESISTANCE Indicates an ink that resists re-softening when printed on sheets that will later pass through the hot fuser rollers of laser printers or copiers. Not all inks are laser resistant, contact Graphic Ink for more details.

LED-UV Similar to H-UV except high output LED lights replace the mercury vapor lamp of H-UV, and specially formulated LED-UV inks have greater reactivity than H-UV inks. LED's run much cooler than mercury vapor lamps, they last much longer, and they consume a lot less energy. LED's must be cleaned on a regular basis to maintain proper curing. Contact Graphic Ink Company for LED-UV sheetfed inks.

LENTICULAR PRINTING A printing method that produces 3-D effects, simulated motion, or images that alternate with the angle of viewing. The procedure usually involves offset printing on lenticular plastic sheeting, and sometimes involves two or more digitally sliced and interlaced images. The interlaced images can be reversed to print directly on the lenticular plastic (smooth side), or can be printed on a substrate and laminated to the lenticular plastic. The precise alignment of the interlaced image with the direction and position of the lines (lenses) in the lenticular plastic is critical for some kinds of visual effects. Contact Graphic Ink for more information on lenticular printing.

LETTERPRESS A printing process that pre-dates litho, where a raised image on an etched plate is inked and pressed onto the substrate to produce the print. Litho inks are not generally recommended for letterpress printing. Today most letter presses are used for sequentially numbering tickets or business forms, die cutting, or for hot-stamping foils to a sheet.  

LIABILITY Due to the speed and complexity of modern printing, losses mount quickly when things go wrong. It is incumbent on the printer to be alert to problems and take action before the problems become catastrophic losses. Vendors cannot be held accountable for losses that occur as a result of insufficient inspections and quality controls in the pressroom. Most vendors will limit their liability to the purchase price of their product unless stated otherwise in writing. See also: “claims”, “guarantees”, and “warranties”.

LIGHTNESS In color mapping, lightness refers to how weak or strong a color is, as from a tint color to a full strength color for example.

LINEN FINISH Refers to paper having a finish that simulates the surface texture of linen fabric.

LINSEED OIL See "flaxseed oil".

LOW MIGRATION See "Migration".

MACHINE FINISH Refers to the smooth uncoated paper surface that comes straight from the paper manufacturing process without further alterations or enhancements.

MAGNETIC INK See "MICR".

MAKEREADY The time and procedures required to prepare the press for printing. This includes the time necessary to make all the adjustments required to produce the first satisfactory press sheet.

MARKING A term used to denote marks or small abrasion like blemishes on the printed sheet caused by the motion of the sheet against some part of the press or print finishing equipment.

MASSTONE How the ink color appears in bulk, such as in the can, in the fountain, or on your ink knives. The color of the ink printed on paper seldom matches the masstone.

MATERIAL SAFETY DATA SHEETS See "MSDS" and "SDS"

MATTE FINISH May refer to paper with an exceptionally dull surface coating, (matte papers). See also "burnishing" and "scuffing". May also refer to a matte finish created by applying special matte coating or overprint varnish to the printed sheet. See also "strike-thru varnish".

MECHANICAL GHOSTING See "ghosting".

METAL FX An old trade name that defined a process of printing over a special base silver to produce a wide range of metallic or pearlescent color effects. Contact Graphic Ink for more on this technique.

METALLIC INKS Inks containing aluminum or bronze powders to produce gold or silver color effects.

METAMERISM The phenomenon where two or more colors match under one light source but not under another.

MICR (magnetic ink character recognition) Magnetic Ink Character Recognition (MICR), as defined by the American National Standards Institute (ANSI), is the common machine language specification for the paper-based payment transfer system. It consists of magnetic ink printed characters of a special design that can be recognized by high-speed magnetic recognition equipment. MICR ink is available from Graphic Ink Company.

MICROMHOS A unit of measure for expressing the conductivity of a substance like water. The higher the micromhos, the more electrically conductive the substance is. Micromhos and conductivity are used to accurately dose fountain solutions with concentrate, since micromhos increase in direct proportion to concentrate added. See also "conductivity".

MICROTAGGANT (See "Taggant").

MIGRATION In food packaging, migration usually refers to the migration of chemicals, taint, or odors, from the packaging materials or processes, to the food product. Migration can potentially affect the taste or odor of a food product, and doesn't necessarily have to involve direct food contact. Preventing migration in food packaging involves controlling not only the materials (inks, coatings, papers, fountain solutions, glues, Etc.), but also the processes used to produce the package, and the environment within which the package was stored, handled, and transported. In many cases, a given material like ink, coating, or paper, may have no migration issues under one set of environmental conditions, but will under another set of conditions. Contact Graphic Ink for more information on migration.

MILL See "ink mill".

MISTING, FLYING A condition wherein a fine mist or spray of ink is thrown off rapidly moving ink rollers.

MOIRE A pattern that sometimes immerges when two or more overlapping screens are misaligned. Moire' can also result from patterns in the image conflicting with a screen used to print the image. Using a printed halftone picture as the original source when re-screening an image can also result in a moire' pattern.

MONOCHROME A single color image that may include a range of tone values, though still produced from a single color.

MOTTLE An uneven "splotchy" pattern showing up in an otherwise smooth and uniform printed area. Some types of mottle affect only screens, other kinds can also effect solids. Mottle is sometimes traced to the paper or to backtrapping or piling; but there can be causes related to blankets, water, and pressure settings. Graphic Ink Co. can help you trouble shoot mottling. See also "backtrapping", "piling", and "K&N absorption test".

MSDS (Material Safety Data Sheets) Documents that provide employees, workers, fire fighters, HazMat responders, and emergency medical personnel, with information about the physical characteristics, safe handling of, and health and exposure risks related to, certain regulated chemicals and materials. Many of our MSDS's can be found on this website under "MSDS".

MUD CRACKING An aqueous coating issue that looks similar to mud drying, typically caused by coating drying too quickly. Contact Graphic Ink for an appropriate recommendation.

NANOMETER The unit of measure used to define wavelengths of light or color. A nanometer is a unit of length equal to one billionth of a meter.

NAPIM National Association of Printing Ink Manufacturers. See our link to NAPIM on this website under "Resources".

NPDC (neutral print density curve) The relationship between measured neutral density and original halftone percentages on a gray scale.

OCR (optical character recognition) The reading of text characters by optical scanners that are coupled with special software that recognizes the characters. OCR inks must be composed of low reflectance pigments, such as carbon black, which can be read by optical scanners. Non-readable inks, though visible to the human eye, cannot be read by OCR readers because they present no reflectance contrast to the machine. OCR inks are available from Graphic Ink Company.

OFF-LINE Refers to a print finishing process that occurs after printing, as a seperate stand-alone process. See by contrast: "in-line"

OPACITY The ability of ink or paint to "blot-out" or "cover-up" what's underneath. The opposite of transparency.

OPTIMIZING SOFTWARE (ink optimizing software) A special kind of software RIP that reduces the amount of cyan, magenta, and yellow, needed to produce four color printing. Optimizing software uses black ink to create what is essentially a black & white image; with cyan, magenta, and yellow, added only to "colorize" the image. Ink optimizing software produces excellent visual results, good color balance, and typically saves 5 to 15% in overall ink costs.

ORANGE PEEL A fine mottle or pinhole pattern caused by ink or coating not laying on the surface well. May be "reticulation". Could also be water emulsified into the ink or too much water on the sheet from a previous print unit. Contact Graphic Ink Company for assistance.

OVERPRINT VARNISH A clear varnish applied over a printed job to improve its gloss and/or mar resistance, etc. Also available in dull or satin finishes.

OXIDIZING INKS Inks that dry primarily by chemical reaction (oxidative polymerization). These inks tend to remain wet until absorbing enough oxygen to dry, at which point they transition quickly to a solid. Usually recommended for plastics, foils, or other non-absorbent substrates. Moisture and low temperatures will slow the drying of these inks. Ask for our "lexan" or "armor" inks.

PACKING MATERIAL Precisely gauged paper or plastic sheets that are placed behind the printing blanket to adjust the amount of "squeeze" on the paper as it passes between the blanket and impression cylinder.

PANTONE A wholly owned subsidiary of X-Rite, Inc. Pantone is the world renowned leader on color exploration, expression, and communication, in the graphic arts arena. Pantones Matching System has long been the standard for designers, ink makers, and printers. Software, hardware, color decks, and other color communication and standardization tools are available from Pantone through Graphic Ink Company. You can link directly to Pantone from this website by going to "Resources" on our home page. See also "Goe" and "Pantone Plus+".

PANTONE PLUS+ A color selection and identification system released by Pantone in May of 2010. The Plus system adds 224 new colors to the traditional Pantone color selection, and re-organizes the entire color palette in a "color intuitive" arrangement as opposed to the traditional numeric arrangement. In a separate color deck, the Plus System also introduces 300 new "Premium" metallic colors, and another deck combines 56 Neon colors with 154 Pastel colors. Order Pantone Plus products from Graphic Ink Company or go to our link to Pantone on our website.

PDCA (Plan, Do, Check, Act) Defines a continuous improvement cycle used in Kaizen and other process improvement methods stemming from the work of Dr. Edwards Deming. PDCA is in practice at Graphic Ink Company.

PERFECTING A term used to describe printing both sides of the sheet in a single pass through the press. The press must be configured for this purpose and the inks must have particular characteristics. Contact Graphic Ink for the appropriate recommendation. See also"piling-back cylinder".

PET (see PETE plastic)

PETE plastic (Polyethylene Terephthalate) PETE plastic, also called PET, is a widely used plastic in food packaging. PETE also lends itself well to recycling, which results in a wide range of PETE based products with post consumer content. Printing on PETE can be challenging, and Corona Treatment is recommended before printing, gluing, coating, Etc. Your plastic substrates should always be pretested prior to printing. Graphic Ink Co can provide pretesting. See also: "Plastics", "Corona Treatment", and "Dyne".

pH (potential for Hydrogen) A measurement of the acidity or alkalinity of a solution or material. The pH scale runs from 0 to 14, with pure water being neutral at 7.0. Less than 7 is acidic, over 7 is alkaline. The pH scale is logarithmic, where the difference between pH 7.0 and pH 8.0 is ten-fold, and the difference between pH 7.0 and pH 9.0 is a hundred-fold. Typical litho fountain solutions are moderately acidic, being between 4.0 and 5.5 pH.

PHOTOCHROMIC INK Photochromic inks can be colored or virtually invisible, but change instantly when exposed to UV light (including sunlight). When the source of UV light is removed the ink reverts back to its original appearance. Very popular for security printing. Available for wet or dry offset and flexographic printing. Contact Graphic Ink for more information.

PHOTOINITIATOR Specialized compounds used in UV inks and coatings which undergo a photoreaction when exposed to ultraviolet light energy. The resulting photoreaction triggers the polymerization of oligomers and monomers, transforming the ink or coating from a liquid to a solid.

PIA (Printing Industries of America) Formerly GATF. The umbrella organization of the graphic arts industry. It is a federation of national, regional, state, and city associations in the printing industry. See our link to PIA on this website under "Resources".

PICKING The de-lamination, separating, or tearing of the paper surface due to excessive ink tack, weak paper fibers or weak paper coating. The shorter fibers of recycled papers often translates to a weaker base sheet. Picking usually leads to blanket piling. Contact Graphic Ink for assistance.

PICTURE FRAMING (framing) The accumulation of slitter or coating dust on the blanket, outlining the edge of the sheet. ALSO, the accumulation of ink on the blanket outside the paper contact area. This condition is usually "tinting" that may not have shown-up on the paper yet. Framing typically relates to fountain solution. Call Graphic Ink Company for trouble shooting assistance.

PIGMENT In printing inks, pigment is what gives the ink its color. Pigments, as opposed to dyes, are finely ground powders, not liquids. Pigment remains a solid in the ink, suspended in the ink vehicle (binder).  

PILING (on the back cylinder) Accumulation of ink material on the impression cylinder in such quantity that it interferes with print quality. Back cylinder piling is frequently associated with 4-over-4 and 5-over-5 perfecting when the appropriate inks have not been selected. Contact Graphic Ink for the appropriate recommendation.

PILING (on the blanket) Accumulation of material on the blanket or plate in such quantity that it interferes with print quality. Blanket piling usually has to do with ink and paper absorption characteristics. Contact Graphic Ink for the appropriate recommendation.

PINHOLES Failure of printed ink to form a completely continuous film. This condition appears in the form of tiny holes or voids in the printed area. Usually the result of too much water, but may also indicate some "reticulation".

PLASTICS Printing on plastics can be tricky business due to the many types of plastics available, and the variations within each type. Some variations will not accept litho printing. Risk factors can include slow ink drying, poor adhesion, static charge, reticulation, emulsification, and blinding. In most cases inks must be specially formulated for plastics. Corona Treatment is very effective, but pretesting ink on substrate is always advised. Graphic Ink Company provides pretesting. See also: "Corona Treatment" and "Dyne".

PLATE BLINDING See "blinding".

PLATE SENSITIVITY When a litho plate begins to take ink in the non-image area. This is usually a plate exposure problem, or a bad or contaminated fountain solution. See also "toning" and "scumming".

PLATE SETTER A device for exposing litho printing plates directly from a digital file.

PLUGGING A problem that occurs when the spaces between type or half tone dots start to fill-in with ink where it is not desired. Plugging can advance to the point that spaces between dots or type fill-in completely to form a solid area. Plugging is usually an ink or fountain solution problem, but can also be plate related, or mechanical in nature. Contact Graphic Ink Company for trouble shooting assistance. See also "slur", "scumming", "TVI", and "doubling".

PMS An "un-official" reference to the Pantone Matching System. Though widely used in pressrooms and elsewhere in the graphic arts industry, this acronym is not sanctioned by Pantone Inc.

POROSITY Refers to how porous a paper surface is. Ink, water, and other liquids, easily soak-into a porous paper surface, whereas a non-porous paper will cause ink and water to stay mostly on top.

POST CURE The tendancy of UV inks to further harden in the hours following initial curing.

PRESSCAKE Pigment (color), that is still in its aqueous phase. Having originally sprung from an aqueous slurry, presscake is what remains after much of the water has been squeezed-out by a filter press. Presscake is a moist, crumbly, mud-like material, which will be dehydrated to make "dry color", or flushed to make "flush color".

PRINT CONTRAST Essentially the difference between density readings taken from the 75% screen patch and the 100% solid patch. The greater the difference, the more contrast will be evident in shadow areas.

PROCESS (process inks or process printing) A popular reference to the method of printing full color images using the four process colors: Cyan, Magenta, Yellow, and Black. Also called "four color process". See also "CMYK".

PROP 65 Restrictions the state of California puts on chemical substances they consider to be carcinogenic, or harmful to reproductive health. The Prop 65 list of restricted substances limits most these substances to under 1000 parts per million (.1%), but some substances are restricted to less than 100 parts per million (.01%).  

PSG (Print Suppliers Group) An association of independent ink companies and graphic arts distributors. See our link to PSG on this website under "Resources". 

PVC (poly vinylchloride) A synthetic white plastic polymer, sometimes made into semi-flexible sheets for printing. There are numerous variations within the PVC family of plastics, and pretesting ink on substrate is highly recommended before printing. Graphic Ink Co. can provide pretesting. See also; "Plastics", and "Corona Treatment".

REACH (Registration, Evaluation, & Authorization of CHemicals) A European Union program of tracking and regulating certain chemicals. Contact Graphic Ink for more information, or go to our link to REACH on this website under "Resources".

REDUCER refers to liquid or paste ink additives that reduce the tack and/or body of the ink.

RETICULATION When ink or coating tries to bead-up on a surface due to incompatible surface tensions. Reticulation often shows up as a rough "orange peel" or a "pinhole" effect. Serious adhesion problems can result from unwanted reticulation; however, reticulation can be an attractive special effect when properly engineered. Special reticulating spot litho varnish is available which causes UV coating to reticulate over the varnish creating attractive visual and tactile effects. Contact Graphic Ink for suggestions. See also "surface tension", "dyne", and "corona treatment".

REVERSE Refers to an image or shape that is created by reversing-it-out of a solid panel of ink. A reverse is essentially a negative, where the image is the area without the ink. See also "knock-out".

RHEOLOGY Having to do with the flow of matter, usually liquids, but also soft solids, or solids that flow rather than deform elastically. Broader in scope than viscosity, rheology also includes aspects of gel, plasticity, and thixotropy. Rheology involves complex data that cannot be expressed as a single value. 

RIP (raster image processor) Software and hardware that converts streams of digital information into fonts and images that are ready for printing. RIP is sometimes used as a verb, as in: "we did a RIP on the file".

RO WATER (Reverse Osmosis) A water filtration process that forces water through a membrane that removes the dissolved solids in the water, allowing the pure water to pass. A typical conductivity reading for RO water would be 20 to 80 micromhos. RO water is preferred over tap water for mixing fountain solutions. See also "conductivity", "micromhos"  and "TDS".

RoHS (restriction of hazardous substances dirctiv) A European Commission initiative for restricting certain hazardous substances in electronic equipment, and for promoting the collection and recycling of such materials and equipment.

ROLLER STRIPPING  See "Stripping".

ROSETTE A rosette is the deliberate arrangement of four-color process halftone dots into a tiny circular pattern, visible under magnification. Rosettes are a common characteristic of "AM screening".

RUB-n-SMELL Specially printed material that releases fragrance when rubbed. Special Rub'nSmell ink, varnish, or coating is required, but no specialized licensing or printing method is necessary. Printing methods include litho offset, flexo, silkscreen, gravure, and anilox coaters. Several dozen stock fragrances are available, and custom fragrances can usually be formulated. Rub'nSmell is available through Graphic Ink Company. Contact us for more information or go to our link to "Scentisphere" on the "Resources" section of this website. See also: "Scratch-n-Sniff".

RUB-OFF SILVER See "scratch-off silver".

RUBBERBASE A term referring to a type of duplicator ink based on rubber resins which don't dry hard but set quickly on bond papers. Rubberbase inks don't contain driers and are in limited use today due to their higher cost and their tendency to re-soften and track when exposed to heat from laser printers and copiers.

SATIN FINISH May refer to paper with a low-gloss surface, or to a satin finish created by applying satin coating or overprint to the printed sheet. Satin is a semi-dull finish as opposed to a matte or dull which is very dull. See also "strike-thru varnish".

SBS (Solid Bleached Sulfate) A fully bleached paperboard stock, clay coated on one side to enhance smoothness and printability.

SCRATCH-n-SNIFF Special ink, varnish, or coating, that releases fragrance when the printed image is scratched to rupture tiny scent-containing cells in the ink, varnish, or coating. The Scratch & Sniff material is not usefull in offset litho printing, but works well when applied as a finish coating, or by flexo or screen printing. See also: "Rub'nSmell".

SCRATCH-OFF SILVER (sometimes referred to as "contest silver") A specially formulated silver ink that will scratch-off a specially coated surface to reveal a message underneath. Best results are achieved using a silk-screen printing method.

SCREEN In printing, a screen is the area of an image that is made up of tiny dots of varying size or frequency, which creates varying tones from dark to light. See also "halftone", "AM screening", "stochastic printing", and "concentric screening". Regarding problems with screens see "plugging", "slur", and "doubling".

SCUFFING The disrupted appearance of an ink film as a result of abrasion to either the wet or dry ink film; or, the transfer of ink from one surface to another as a result of pressure and friction between them. Scuffing is commonly associated with dull or matte papers, but can usually be prevented by applying overprint varnish or coating. See also "burnishing" and "chalking".

SCUMMING A condition where the plate goes sensitive in the non-image area causing ink to print where it doesn't belong. Scumming will not wash-off the plate easily with water. If the scumming washes-off the plate easily, you are more likely dealing with tinting. Scumming is almost always a fountain solution problem, but can also result form improper plate exposure or processing. See also "plugging" and "toning".

SDS (Safety Data Sheet) Documents that provide employees, workers, fire fighters, HazMat responders, and emergency medical personnel, with standardized information about the physical characteristics, safe handling of, and health and exposure risks related to, certain regulated chemicals and materials. SDS's replace the earlier "Material Safety Data Sheets" (MSDS).

SEEDING Refers to an ink or varnish that develops a grainy or lumpy appearance in the can over time. Seeding can look bad but seldom translates to a printing problem because it smoothes-out so easily in the roller train. Re-milling the ink also smoothes-out seeding, but it will return again with time. Seeding is somewhat rare, but results from chemical and/or biological reactions to certain temperature, humidity, and storage conditions.

SET-OFF (blocking) Printed sheets sticking together in the pile. Possible causes include: too much ink being applied, ink setting too slowly for conditions, ink is water-logged and not drying properly, substrate is not absorbent, stack temperature is too high, stack pile is too high, faulty offset powder or powder unit. Contact Graphic Ink for assistance in diagnosing the cause and prescribing a solution.

SETTING Refers to the characteristic of some inks to loose their "wetness" shortly after contact with the paper. Setting occurs more rapidly on gloss enamel papers than on bond papers.

SFI (sustainable forest initiative) An independent organization dedicated to promoting sustainable forest management; also providing audits and certifications to producers and users of forest products. Contact Graphic Ink for more information, or go to our link to SFI on this website under "Resources".

SHEETWISE A way of printing both side of the sheet that involves changing the plates for the second side, but turning the sheets left-to-right to maintain the same gripper edge on the second pass. See also "work-and-turn" and "work-and-tumble". Whether the job involves sheetwise, work-and-turn, or work-and-tumble, depends on how the job was layed-out in the planning stages.

SHORT A term sometimes used to describe the body or structure of a litho ink that has little flow. When a short bodied ink is pulled-on by an ink knife, it doesn't stretch into a long string, but breaks-off short.

SHRINK SLEEVE A way of covering a bottle, or odd shaped container, with graphics that are flexo printed on a shrink-film plastic sheeting. The printed film is formed into a cylinder shaped sleeve that fits around the bottle or container, where upon heat is applied to shrink the film tightly to the container. Special shrinksleeve inks are required.

SKIN PACKAGING A packaging method that uses heat and vacuum to shrink-wrap a thin plastic film around a product and onto a rigid paperboard platform (usually a printed piece). A special paperboard stock and special inks are required for this process. Contact Graphic Ink for the appropriate inks. See also "blisterpack" and "clamshell".  

SKINNING The formation of a dried layer on the surface of a fluid such as an ink or coating after a period of standing.

SLIDE ANGLE A measurement of the amount of "slip" between two surfaces placed face-to-face. Expressed as the degree of slope angle at which the two surfaces break-loose and slide while under pressure. COF is often a consideration in selecting the appropriate coating. See also: "COF"

SLUR A mechanically caused distortion, smearing, or elongation of the printed image or halftone dots. Slurring is an indication of mechanical movement in the plate, blanket, or press cylinders. Can also be attributed to improper packing or excessive pressure between the plate and blanket, or the blanket and impression cylinder.

SNOW FLAKING Fine white specks that appear in offset printing, usually caused by water droplets remaining in the printing nip during impression.

SOFT FEEL (Soft Touch) COATING An aqueous or UV coating that produces a satin finish that feels soft like "rubber". Cross-linker is recommended for (aqueous) Soft Feel where two-sided work is involved. Inks need more time to dry when overcoated with (aqueous) Soft Feel, and spot UV should never back-up Soft Feel due to the risk of "ghosting". Ask for our Tech Sheet on "Soft Feel Coating". Soft Feel is available from Graphic Ink in Aqueous, Heatset, or UV formulations. See also: "cross-linker".

SOY (soybean oil) A vegetable oil derivative of soybeans. Soybean oil is common in most oilbased sheetfed litho inks today, usually in combination with other vegetable oils. The soy content varies depending on performance requirements such as setting speed, drying time, and hardness.

SPECTROPHOTOMETER An instrument for analyzing color wavelengths. The spectrophotometer reads the intensity of electromagnetic radiation at different wavelengths to create a spectral "curve" that serves as a kind of "fingerprint" for that color. The spectrophotometer is recognized as the best color analysis tool. See also "nanometer".

SPECTRUM See "Color Spectrum".

SPOT COLOR A stand-alone color (like a Pantone color), not produced by four color process. Spot Colors are sometimes referred to as a "5th color". Custom matched colors are usually Spot Colors too, as are metallic and fluorescent colors.

SSOP (sanitation standard operating procedures) Written procedures that describe the cleaning and sanitation practices employed anywhere food or food packaging is produced or processed. SSOP is covered by 9 CFR 416.11-416.16 (Code of Federal Regulations). See also "HACCP" 

STEREOSCOPIC EFFECT A 3-D effect created when one eye sees a slightly different perspective (or image) than the other eye. See also "lenticular printing".

STOCHASTIC PRINTING (also called FM screening) A method of varying tone values in a screen by increasing or decreasing the number of dots, as opposed to varying the size of the dots as in conventional screening. The term "FM" comes from "Frequency Modulation", meaning the Frequency of the dots is Modulated to control tone values. There are advantages and disadvantages for each screening method. See by contrast "conventional screening (AM)". 

STRIKE-THRU VARNISH This is a spot overprint varnish that prints in a litho unit just before gloss aqueous coating is applied. Where the Strike-thru has been printed, it comes-through the gloss coating as dull. Strike-thru varnish is available from Graphic Ink Company.

STRIPES / STREAKING Areas in ink or coating that appear as linear density variations. Stripes may occur vertically or horizontally on the sheet depending on the cause. Contact Graphic Ink for trouble shooting assistance.

STRIPPING (roller stripping) A condition in which the ink fails to adhere to, and distribute uniformly on, the ink rollers of the press. Stripping usually shows up as bands or stripes of missing ink that run around the roller as opposed to horizontally across it. Roller stripping occurs when ink rollers develop an affinity for water, which prevents ink from sticking to them. The usual cause is a buildup on the ink rollers of water soluble contaminates from the paper, ink, or fountain solution. Calcium is the usual suspect, coming from tap water or the paper. A good calcium wash and roller deglazing will usually cure roller stripping. See also "complexing solution" and "calcium wash".

SUBLIMATION INKS (heat transfer) Special inks that are printed on paper and are later ironed onto fabric using heat and pressure. Sublimation inks are available from Graphic Ink Company.

SUGAR TEST See: Brix Test

SURFACE TENSION The property of liquids to form a cohesive force at their surface, which causes them to pull together as droplets as opposed to flowing-out freely. If the surface tension of a liquid is higher than the surface energy of a substrate, the liquid will tend to bead-up on the substrate. In litho printing, the surface energy of the substrate should be more than 35 dynes. Graphic Ink can test the dyne level of your substrate upon request. See also "reticulation", "dyne", and "corona treatment".

SUTHERLAND RUB TESTER An instrument that rubs two surfaces together under controlled conditions to determine the scuff resistance of the surface(s). The surface area, pressure, and the number of strokes are all controlled. Sutherland rub test is the usual method for evaluating the durability of printed surfaces. Evaluation is by visual assessment.

TACK Refers to the "stickiness" of the ink or coating. In other words, tack is how much a wet ink or coating film resists being split or separated. An "Inkometer" is an instrument for measuring tack under controlled conditions.

TAGGANT (microtaggant) A kind of "marker" imbedded in ink, coating, glue, or substrate. Taggants are popular in security printing, and are usually for authenticating a product. There are several kinds of Taggants ranging from magnetic, to optical, to X-ray, to UV, among others. Some Taggants can be programmed with complex codes that get registered (similar to a barcode). The Taggant is usually read by an instrument; sometimes a hand-held instrument like a laser, sometimes a sophisticated laboratory device. 

TAILING Tiny stringers of ink tailing-off the trailing edge of type or solids, caused by too heavy an ink film being applied. ALSO: Downward curling of the sheet at the delivery end of the press caused by the stress of pulling the sheet from the blanket when excessive tack or clinging is taking place.

TDS (total dissolved solids) The amount of organic or inorganic material dissolved in water at the molecular level, small enough to pass through a 2 micron filtration screen. TDS can be approximated by measuring the electrical conductivity of the water using a conductivity meter. The higher the conductivity, the higher the concentration of dissolved solids. See also "conductivity", "micromohs", "RO water", and "DI water". Solids too large to pass through a 2 micron filter screen are considered TSS (total suspended solids).

THERMOCHROMIC INKS Inks that change color, appear, or disappear, with changes in temperature. Available by special order from Graphic Ink Company.

THERMOGRAPHY A process that involves a special powder applied immediately after printing that is heated to produce a raised type effect. Usually a clear material, but also available in metallic and pearl effects. Thermography requires specialized equipment for applying, removing, and heating the thermographic powder.

THIXOTROPY A property of some non-newtonian pseudoplastic fluids (like litho ink), to exhibit a higher viscosity at rest (resting viscosity), than under working conditions (working viscosity). Two inks of the same working viscosity may exhibit different resting viscosities; however, the emphasis is on working viscosity because that's where printing takes place. See also: "yield value", "rheology", and "Laray viscometer".

THUMB-TWIST TEST A simple test for determining if coating and ink are completely dry. With your thumb wiped clean and dry, put all the pressure your thumb can bear against the printed surface and twist (a half or three quarter turn). Fully dried ink and coating will not smudge.

TINTING The bleeding of ink pigment particles into the dampening solution, often resulting in a slight discoloration of the sheet. Tinting wipes-off the plate easily with a damp rag; if not, you are likely dealing with "toning" or "scumming". Contact Graphic Ink for ideas on how to eliminate tinting.

TONING A light scumming condition on a press sheet characterized by ink in the non-image areas of the blanket, paper, and eventually the plate. Toning stems from bad fountain solution (sometimes contaminated by the paper), poor plate exposure or processing, or ink water-logging. Ask our technical department about "Complexing Solution" or "buffers" as possible remedies. In waterless litho printing, toning can result from the ink rollers not being chilled enough, improper plate exposure or processing, or having the wrong ink. Contact Graphic Ink for ideas on how to diagnose and eliminate toning. See also "CTI", "scumming", "buffers", and "Complexing Solution".

TRAPPING (dry) The ability of a dry ink film to accept a succeeding ink film.

TRAPPING (wet) The ability of a freshly printed (wet) ink film to properly accept a succeeding ink film.

TSS (total suspended solids) The amount of solids suspended in a liquid like water, fine enough to remain in suspension without settling-out, but large enough to be caught in a 2 micron filter screen. See also "TDS".

TUNG OIL (also known as chinawood oil) A vegetable oil derivative of the nuts produced by the aleurites fordii shrub. Due to its higher cost, tung oil is generally reserved for inks requiring exceptionally hard drying.

TVI (tone value increase) (Formerly known as DOT Gain) The reflection halftone percentage measured on a printed sample minus the original half tone percentage file value that produced it.

UCR (under color removal) Using black to replace a small percentage of the other process colors where possible.

UNFREAK'n BELIEVABLE!! An expression of astonishment over the high level of customer service provided by Graphic Ink Company. Often accompanied by disorientation and a sense of bliss and euphoria.

UV COATING A very slick, glossy, and durable plastic coating, applied as a liquid over the printed sheet, and dried instantly with ultraviolet (UV) light. Also available in dull, satin, and other special effects.

UV INKS Inks specially formulated to dry instantly with ultraviolet (UV) lights installed on the press. UV inks are available from Graphic Ink Company in Process & Spot colors. See also "H-UV" and "LED-UV".

VEHICLE (Sometimes called varnish) In printing ink, the vehicle is the glue that holds everything together. The vehicle is the backbone of the system, "carrying" the other formula components to the substrate where it anchors everything down and hardens.

VELLUM In papers, vellum finishes are a course, toothy, uncoated finish that tends to soak-up ink.

VIGNETTE A regressive halftone screen that moves across the entire tone scale from dark to light. Accent shadows around type are usually small vignettes added for 3-D effect.

VISCOSITY A measure of a materials resistance to flow. See also "rheology", "yield value", and "Laray viscometer".

VMP (vacuum metallized pigment) Specialized metallic pigment used to produce metallic inks of exceptionally high metallic brilliance. Though very expensive, VMP inks can replace foil stamping in some cases. Available from Graphic Ink Company.

VOC's (volatile organic compounds) Organic compounds with enough vapor pressure to vaporize into the atmosphere under normal conditions. In litho sheetfed inks, VOC's are high boiling point petroleum distillates (mineral oils), used to control tack & setting speed. Though early quickset inks contained as much as 30% VOC's, today few sheetfed litho inks contain more than 15 or 20% VOC's, and most contain less than 10%. Popular "Bio inks" from Graphic Ink contain only trace amounts of VOC's (about 2%).

WARRANTIES Warranties regarding printing inks offer assurance that the ink will meet certain specifications, not necessarily certain outcomes. Warranties on inks usually limit liability to the purchase price because variables outside the ink company’s control affect ink performance, and losses can be out of all proportion to the inks roll. See also: “claims”, “guarantees”, and “liability”.

WATERLESS INKS (driography) These are litho inks that can run without water or fountain solution. Special inks, special waterless plates, and chilled rollers, are required. Waterless inks are available from Graphic Ink Company.

WAX Wax in ink greatly enhances rub resistance. Too much wax however can inhibit the adhesion of coatings and foil stamping, and can diminish the laser resistance of the ink. 

WIRE SIDE Specifies the side of paper that was against the wire mesh during the paper manufacturing process. The opposite side is referred to as the "felt side". 

WORK-and-TUMBLE When the second side of the sheet is printed with the same plates as the first side, but the sheets are turned over front-to-back for the second pass. See also "work-and-turn" and "sheetwise". Whether the job involves work-and-tumble,  work-and-turn, or sheetwise, depends on how the job was layed-out in the planning stages.

WORK-and-TURN When the second side of the sheet is printed with the same plates as the first side, and the same gripper edge is maintained by turning the paper over left-to-right rather than front to back; which helps maintain better register. See also "work-and-tumble" and "sheetwise". Whether the job involves work-and-turn, work-and-tumble, or sheetwise, depends on how the job was layed-out in the planning stages.

YIELD VALUE The point at which a substance like lithographic ink will "yield" to a force like gravity and begin to flow. Yield value correlates well to how "thick" an ink seems to be when at rest in the can, but Yield Value is not a good indicator of the working viscosity of the ink on press. See also "rheology", "viscosity", "thixotropy", and "Laray viscometer".

ZAHN CUP A devise for measuring low viscosity liquids like coatings. Viscosity is expressed as the number of seconds required for the cup to empty to the point the flow stream breaks. Various sizes are available for different ranges of viscosity.