Aa

a
metric symbol for atto.

AA
abbreviation for "author’s alteration," denotes a change required from the original copy., also referred to as artist’s correction.

A-stage
an early stage in the reaction of a thermosetting resin where the material is still soluble in certain liquids and fusible, also reference B stage and C stage.

abscissa axis
the x coordinate.

aberration
(1) a disturbance in color that interfere with clarity, typically one of the faults found in interpolated colors; (2) errors in a photographic lens which prevent the lens from producing a single focus of all intensities of the light rays reflected from the subject, resulting in poor image definition at the film plane.

A-board
a double-faced sign with each face mounted on a frame so that the two, with tops lined together and bottom held in separated position with a brace, form an "A" when viewed from the side.

abherent
a substance that prevents adhesion of a material, either to itself or to other materials; a release agent, such as silicone or wax.

abrasion resistance
the inherent ability of a surface to inhibit deterioration or destruction by friction, also referred to as rub resistance.

abrasion test, paper
paper used to determine dry rub, wet rub, wet bleed, smear, and rub qualities, incorporating several types of motion, also used for the testing of surface areas, under a variety of load conditions.

abrasion test, textile
used for testing a specific textile application such as piling, scrub resistance, fabric adhesion, and chalking.

abrasion test, washability
used to determine the scrub resistance, washability, cleanability, and abrasion resistance of coating materials such as waxes, anodized metals, and plastics.

abrasiveness
the tendency of a material or coating to abrade or wear away a surface or an edge.

ABS
an acroynm for acrylonitrile-butadiene-styrene copolymers.

absolute humidity
the actual weight of water vapor contained in a unit weight of air, expressed in grams per cubic meter.

absolute register
high degree of exact size conformity of all image elements with the original or with position on the substrate.

absolute viscosity
a characteristic of one-component liquids which have a constant ratio of shear stress over shear rate (constant viscosity).

absolute white
in theory a material that perfectly reflects all light energy at every visible wavelength; in practice a solid white with known spectral data that is used as the "reference white" for all measurements of absolute reflectance. (When calibrating a spectrophotometer, often a white ceramic plaque is measured and used as the absolute white reference).

absorbance
an index of the light absorbed by a medium compared to the light transmitted through it; numerically, it is the logarithm of the ratio of incident spectral irradiance to the transmitted spectral irradiance, a unitless number. (Absorbance implies monochromatic radiation, although it is sometimes used as an average applied over a specified wavelength range).

absorbency
that property of a porous material such as paper that causes it to take up liquids or vapors (e.g., moisture) with which it is in contact, allowing penetration into its bulk.

AC
abbreviation for author’s correction, also referred to AA; standard acroynm for air conditioning and alternating current; refer to current, alternating.

ACGIH
acroynm for American Conference of Governmental Hygienists.

accelerate
to hasten the natural progress of an event or a series of events such as the addition of a faster drying solvent or increasing the temperature or volume of air to dry the printed surface.

accelerated aging/weathering
laboratory test methodology that simulates long term environmental effects, but at the same time intensify and accelerate the destructive action of natural weathering in an attempt to produce changes in the material similar to those observed after continuous outdoor exposure. (Test involves exposure to artifically produced components of natural weather, light, heat, cold, water vapor, and rain which are controlled and repeated in a given cycle).

accelerator
(1) a substance added, or method used, to hasten the natural progress or process of an event or series of events, such as ink drying; (2) material that when mixed with a catalized resin, will speedup the chemical reaction between the catalyst and resin, either in polymerizing of resin or vulcanization of rubber; also referred to as a promoter.

Acceptable Quality Level (AQL)
the maximum number of defects per one hundred units that can be considered to be satisfactory as a process average.

acceptance sampling
the evaluation of a definite lot of material or printed product to determine its acceptability within quality standards.

accessory
supplementary part or equipment, something nonessential but useful.

accordion fold
a series of parallel folds where each fold opens in the opposite direction from the previous fold like the bellows of an accordion.

accurate
without error, precise, exactness to a specific degree or size, true to given dimensions.

accuracy
(1) the deviation of the measured or observed value from the accepted reference; (2) the total of all deviations from a specified straight line; usually the sum of non-linearity, repeatability, and hystersis expressed as a percent of full scale output.

acetal (POM)
a highly crystalline thermoplastic resin polymerized from formaldehyde that is formed from combining aldehydes and alcohol; generic name of polyoxymethylene.

acetate
(1) a plastic synthesized from acetic acid that exhibits rigidity, dimensional stability, and ink receptivity; made from cellulose acetate or its derivitives such as the clear plastic covering placed over artwork; (2) a family of solvents, also known as esters.

acetic acid
an organic acid used in testing acid resistance of a material; photographic, the active ingredient in stop bath or fixing baths.

acetate butyrate
an extruded thermoplastic that can be decorated and heat-formed.

acetone
colorless, highly flammable chemical compound (CH₃)₂CO used as an organic solvent, an ingredient in many lacquer thinner compounds and adhering liquids; used to remove lacquer adhered knife-cut stencils and lacquer type blockout from screen fabrics.

achromatic color
a neutral color (white, gray, or black that has no hue).

achromatic color reproduction
color separation technique whereby the neutral compound is digitally replaced by a corresponding level of black; also refer to gray component replacement.

achromatic lens
a lens corrected for black and white photography; specifically one that brings visual rays to the same focus.

acid
any substance in an aqueous solution capable of turning litmus indicator red, disolving certain metals to form salts, reacting with base or alkali to form salt, below 7 pH.

acid dye
textile printing color containing salts of organic acids and used for applying color to protein fibers such as silk, wool and polyamides.

acid etching
producing images by using acid and resist materials.

acid fixer (fix) (fixer) (fixing bath)
a chemical solution containing sodium thiosulfate and diluted acetic acid that renders photographic images on film or paper permanent, upon immersion for the prescribed time by removing unexposed silver halides; also refer to hypo.

acid free paper
a paper with no acidity or residual acid producing chemicals.

acid number
a measure of the amount of free acid on a molecule, calculated as the number of milligrams of potassium hydroxide required to neutralize the free acids in one gram.

acid proof (acid resistant)
quality of a material that prevents or lessens the effect of contact or immersion in acid.

acid resist
coating used mainly in printed circuit production that is resistant to etching solutions; also refer to etch resist.

acid stop bath
a photographic solution, generally acetic acid, used for stopping the action of the developer on a photographic positive, negative, film or paper.

acid wash
chemical mechanical process where dye is taken out of a garment, producing a splotchy look that can range from large to a very fine; also referred to as rough cutting a garment.

ACL
acronym for applied color labeling.

ACL lug
a small protrusion or depressed cavity manufactured in containers to act as a guide in positioning decorations; also refer to ramp.

acquire
computer command, typically under "File" menu, that allows the start of scanning software directly from the application. Acquire is only available if the software is TWAIN-compliant.

across grain
a direction that is 90 degrees to the machine grain imposed in the making of paper from fiber; also refer to cross direction.

acrylate
an ester or salt coming from acrylic acid; a type of monomer used in UV ink and coating formulations that contains the chemical group CH₂=CHCO₂H.

acrylic (PMMA)
(1) thermoplastic resin from polymerization of acrylic or methacrylic acid esters that exhibit fairly high impact strength, rigidity, and compatibility with other plastics; (2) used as base compound in formulating ink and adhesive systems; (3) synthetic fiber created as a substitute for wool, resistant to shrinking, moths, sunlight and chlorine degradation; wool-like hand, machine washable and dryable, excellent color retention.

acrylic based adhesive
a pressure sensitive adhesive based on acrylic polymers.

acrylic emulsion
a water based latex made with acrylic polymers used for coatings and/or impregnating.

acrylic ink
ink containing acrylic polymers used for screen printing on some plastics and other substrates, especially where outdoor exposure is involved.

acrylonitrile-butadiene-styrene (ABS)
a thermoplastic derived from acrylonitrile, butadiene, and styrene, the strongest of the styrene copolymers and the most widely used.

actinic light
a ray of light that is composed of short wavelengths as found in the ultraviolet and violet areas of the spectrum; capable of changing the properties of photosensitive materials on exposure to the light source.

activate
to accelerate a reaction or increase chemical activity.

activated carbon
a powdered or granular carbon that is highly absorbent, used to remove organic vapors and odors.

activated sludge treatment
a water effluent waste treatment employing forced air to accelerate biodegradation process.

activator
(1) a chemical used to accelerate a reaction or increase chemical activity in another material; (2) in photography, a high pH solution that allows diffusion of the developer into the film emulsion for development of the image.

active component (active devise):
a part or element in an electronic device that controls current or voltage to produce gain, impede or resist flow, or provide switching action in a printed circuit.

active substrate
a substrate or base for an integrated circuit component where parts of the substrate display voltage or current control to accomplish gain, impedance, or switching.

activity
in thermodynamics, the active concentration of a free ion in solution.

actuation force
(1) the amount of pressure necessary to close a membrane switch, measured in grams; (2) the force required to collapse the walls of a rubber keypad, metal, or polyester dome.

acutance
the acute details of shape or sharpness of the edge of a printed line or dot.

acute
a toxic effect that results from a short term exposure to a very high concentration of a toxic substance.

acute effect
the adverse effects that normally are evident immediately, or shortly after exposure to a hazardous material, generally no longer than 14 days.

adaptive compression
A type of compression software commonly used to back up files. The method of compression will change with the type of file, and is not recommended for photographic images because it may destroy original data.

additive
a substance added in small amounts to another to improve desirable qualities or surpress undesirable properties, or otherwise changes the composition to a predetermined state.

additive lamps
a medium pressure mercury vapor UV lamp (arc or microwave) that has small amount of metal halide added to the mercury. (These materials will emit their characteristic wavelengths in addition to the mercury emissions).

additive color matching
process that can specify colors in terms of the three numbers representing the amounts of the three primary lights added together to make a match. (The amounts of the three primaries, expressed in numerical form for each primary and describing the new color, are known as the tri-stimulus values of that color).

additive primary colors
red, green, and light blue; when all additive primaries are combined at 100% intensity, white light is produced; combining at varying intensities produces a gamut of different colors.

addressable resolution
the highest resolution of a printer, scanner, etc. in working with an image, also refer to optical resolution and interpolation.

adherend
any item that is attached to another item or surface by an adhesive.

adhering liquid
a solvent used for attaching lacquer-filled knife-cut stencil film to the screen mesh, usually a blend of lacquer-type solvents.

adhesion
the molecular force of attraction between unlike materials; being united or attached, by a mechanical, chemically, or reactive bond between surfaces causing them to stick together; (adhesion to a smooth surface may rely on polar adhesion).

adhesion buildup
an increase in the peel adhesion value of pressure sensitive tape after it has been allowed to dwell on the applied surface.

adhesion, chemical
the attachment of an ink or coating to a surface by actual chemical attack which changes the character of the substrate.

adhesion, intercoat
the ability of inks and coatings to adhere to one another.

adhesion, intracoat
the ability of an ink or coating to maintain its integrity without separating or layering.

adhesion, mechanical
(1) attraction between two surfaces that is promoted by a physical interlocking (plastisol adheres to fabric by such bond after curing); (2) an attachment of a ink or coating film to a surface by molecular attraction without altering the coated surface.

adhesion, peel
a measure of the force required to remove a material from a test panel at a specified angle and speed after the material was applied to the panel under specific conditions.

adhesion shear
a measure of the time required to slide a standard area (as of a decal) from a standard flat surface in a direction parallel to the surface.

adhesion, specific
the force required to remove a decal adhesive from a specified substrate under specified conditions.

adhesion test
any of a variety of test methods used to determine adequate bonding of ink or coating to a substrate.

adhesion ultimate
the mature bond established under controlled conditions between the tacky surface of a decal (or similar) and a substrate.

adhesive (glue)(cermet)(gum)
a substance capable of holding materials together by surface attachment.

adhesive bleed (ooze)
adhesive exudation from pressure sensitive stock before or after processing to finished product, as a result of cold flow or clamp pressure.

adhesive cold temperature, adhesive high temperature
an adhesive that will induce a bond to a cold substrate or respectively a hot substrate.

adhesive, layflat
an adhesive having the property of resistance to warping in laminations.

adhesive, permanent
an adhesive with relatively high ultimate adhesion properties.

adhesive, pressure sensitive
a type of adhesive that in dry (solvent free) form is aggressively tacky at room temperature with the capability of inducing a bond with dissimilar surfaces on contact with slightly firm pressure.

adhesive, removeable
an adhesive characterized by high cohesive strength and low ultimate adhesion strength.

adhesive residue
(1) adhesive deposit remaining on substrate due to cohesive failure when a pressure sensitive material is removed; (2) adhesive remaining on water-applied decal after application to a surface.

adhesive, temporary
an adhesive characterized by relatively short ultimate adhesion.

adjacency effect
(1) property of the eye that causes the same color to look different when surrounded by or adjacent to other colors, such as a color will appear darker when surrounded by a lighter color, or lighter when surrounded by a darker color; (2) alterations in exposure densities within a silver halide film emulsion that occur during processing at the conjunction areas of differing densities.

adjustable camera
a camera with manually adjustable distance settings, lens openings and shutter speeds.

adjustable mesh holder
refer to adjustable frame.

adjustable focus
describes a camera lens that has adjustable distance settings.

adjustable frame
an adjustable screen printing chase with side members capable of moving toward or from the center of the chase, to which the mesh is attached for tensioning or register control; refer to retensionable frame.

adjustable stroke
a means of mechanical control of the distance that the squeegee travels in screen printing.

adsorption
(1) the concentration of molecules of a particular kind of the inter-face between the pigment and vehicle in screen printing inks, can effectively remove a component such as the drier from an ink vehicle; (2) a surface phenomena, in which liquid or gaseous molecules are retained on the surface of another substance; (3) the adhesion of molecules to a surface; (4) an effect of light striking an object where the light energy is absorbed and re-emitted at longer wavelenghts; (5) in optics, the loss in transmission of light, as through a transparent or translucent material.

advertising specialty
any novelty item that can be imprinted, and usually given to customers as a promotional article.

affected facility
within the meaning of the Clean Air Act (US), refers to a stationary source of air pollutants, or any apparatus to which a federal standard is applicable.

affinity
the attraction between an adhesive and an adherent.

after burner
an air pollution device that removes noxious gases and vapors through incineration.

after tack
stickiness that develops in an ink film after it has apparently dried, or after a heat drying operation.

against the grain
at right angles to the grain direction of the paper.

agate
unit of measurement for depth of columns for advertising space; 14 agate lines equals one inch (2.54 cm).

agate burnisher
an agate tipped tool used for rubbing and polishing silver and gold decorations.

age resistance
to resist deterioration from oxygen, ozone, heat, light, or internal chemical action.

agglomerate
to collect or gather particles in a weakly bonded mass; a clustering of undispersed particles usually pigments.

aggregate
to collect or gather in strongly bonded mass.

aggressiveness
a means of comparatively categorizing adhesive products by degree of tackiness and speed with which bond occurs.

aging
(1) the change or changes undergone by a material as a result of the passage of time; (2) (steaming) the curing of screen printed decorations on textiles by application of moist heat to fix the colors into the fibers and to remove the stiffness (hand) induced by normally air dried imprints.

agitation
keeping a solution, or a substance in a solution, in motion during processing.

air bells
(1) surface defects in paper, sometimes called blisters or foam marks; (2) air bubbles sometime found in photo emulsion after stirring in sensitizers.

air brush
(1) a pencil-shaped device for spraying liquid by means of compressed air, used for retouching photographic prints to improve tonal value, for spraying inks, or for producing special effects on film positives; (2) a tool found in most graphic software packages that provides the effect of spraying a paint air mixture over an image.

air bubbles
bubbles of air adhering to the surface of a photographic negative, positive, carbon tissue, etc., when surface is immersed in solution.

air conditioning
regulation by mechanical means of temperature and air circulation within a selected enclosed area.

air contaminant
any substance of either man-made or natural origin in the ambient air such as dust, gas, fumes, mist (other than H₂O), smoke, heat, and noise.

air dried pigment
pigment/resin combination capable of drying at room temperatures, with or without agitation of surrounding atmosphere by fan or other mechanical means.

air-gas ratio
volume of air per unit volume of gas in a mixture supplied to a gas burner.

air jet
refer to air knife.

air knife
the tiny holes or slots in the sheet, plate, or similar configuration within a drying system through which air is forced under compression onto the surface of freshly printed substrate to accelerate drying; also referred to as air jet.

air permeability
relative ability of a material to permit air flow, or to breathe.

air pollutant
dust, fumes, mist, smoke, and other particulate matter, vapor, gas, odorous substances, or any combination thereof.

air pull
coating the ink over the screen without making an impression on the substrate; also refer to flood coat, flood stroke, flooding.

air recovery
a process of capturing airborne contaminants such as smoke, dust, and solvent vapors.

akimbo
refer to double wing easel.

alabaster glass
a milky, white glass that diffuses light without fiery color.

alcohol
any of a class of chemical compounds derived from hydrocarbon by replacing one or more of the hydrogen atoms with an equal number of hydroxyl radicals; a class of solvents that in addition to the hydrogen and carbon elements, also have oxygen, general formula C₂H₅OH.

aliasing
a visual stair stepping of image edges caused by too low of a resolution for the size of the output.

alignment
the act of aligning or the condition of being aligned; in typesetting, denotes the exactly even relationship at the top or bottom of letters of a font; can also refer to the setting of lines of type, so that their ends appear even, refer to justify.

aliphatic hydrocarbon
commonly known as paraffins; a group of petroleum naphtha solvents that are straight chain or open chain hydrocarbons, such as petroleum ether, pentane, hexane, cyclohexane, mineral spirits, Stoddard solvent, kerosene, V M & P, mineral spirits, and lacquer diluents.

aliphatic solvent
a straight-chain solvent derived from petroleum of low KB (Kauri Butanol) value such as mineral spirits and Stoddard solvent.

alkali
any chemical that reacts on contact with an acid; capable of neutralizing acids; pH greater than 7.

alkali blue
refer to reflex blue.

alkaline dip
term used for that step in stripping or removing of an alkali soluble resist when an etched circuit board is dipped and soaked in a high strength (6-10%) solution of a sodium hydroxide, softening the resist which is subsequently removed in a separate water rinse.

alkali removeable
resist ink, which when dry, are removable by application of a caustic compound or alkaline solution.

alkali resistance
the relative ability to resist the action of alkalis.

alkali test
used to evaluate the resistance of printed labels to alkalis.

alkyd
a group of synthetic resins formed by condensation of polybasic acids with polyhydric alcohols, modified with drying oils for printing ink manufacture.

alkyd plastic
thermoset plastic based on resins composed principally of polymeric esters, where the recurring ester groups are an integral part of the main polymer chain, and where the ester groups occur in most cross links that may be present between chains.

allergen
a chemical to which an individual may be, or become, abnormally sensitive.

alligator
the effect of a surface film contracting during drying to form small, irregular islands of color somewhat resembling the texture of alligator skin, also referred to as orange peel.

all-over printing
the technique of covering the entire front and/or front and back of a garment with a printed image.

alpha
(1) the average percent change in resistance per degree of a pure metal resistance device between 0 degrees and 100 degrees Centigrade, which is usually designated by the Greek letter A or a, with units of ohm/ohm/C; (2) the mask channel in a color system.

alpha blending
ability to specify a fourth color component in addition to RGB, used to specify opacity, from completely transparent to opaque.

alpha channel
an eight-bit grayscale channel found in some graphics applications or the last eight bits in a 32-bit color scan. (The first 24 bits describe the color of objects. Alpha channels permit layering of images. Some uses include masking objects, making them transparent, or adding specific color instructions).

alphabet length
the space required for the letters of the alphabet in a particular type font.

alphabet sheet
sheet containing fonts of letters that may be removed and relocated to form words and/or lines of copy. (They are either on transparent material having a pressure sensitive adhesive back, or the letters are printed on the back of the sheet and adhered to the new substrate by burnishing).

alphanumeric
consisting of alphabetic and numerical symbols; a device or system that includes letters and numbers.

alter
a change made to an image element, color, or page layout through computer manipulation.

alteration
change in copy or specification made after production has begun.

alternative method
within the meaning of the Clean Air Act (US), any method of sampling and/or analyzing for an air pollutant, which is not a reference (or equivalent) method, but which has been demonstrated to produce results adequate for the determination of compliance with the Act.

alumina
any of several forms of aluminum oxide used as an abrasive and in marking glass, enamel, and refractories.

alumina hydrate
a white inorganic pigment used as an extender in inks and noted for its transparency.

aluminum bronze
finely pulverized aluminum in very small flake form suitable for mixing with a varnish type or lacquer type vehicle for use in screen printing metallic effects.

aluminum ink
a printing ink whose principal pigment consists of aluminum, finely pulverized into flaky particles, and when printed gives a silver color appearance; also referred to as silver ink.

aluminum sterate (oxide)
a principal thickening agent used in many screen printing inks and transparent extender bases.

AMAL
abbreviation for amalgam.

ambient
surrounding environmental conditions such as pressure, temperature, or humidity; environment coming into contact with a system or component.

ambient compensation
the design of an instrument such that changes in ambient temperature do not affect the reading.

ambient temperature
temperature of the immediately surrounding air volume.

American National Standards Institute (ANSI)
a standards setting agency of the United States that approves design and performance of electrical/electronic components (USA).

American Society for Testing & Materials (ASTM)
the world’s largest source of voluntary consensus standards on the characteristics and performance of materials (USA).

American Wire Gauge (AWG
a wire diameter specification where the smaller the number designator, the larger the wire diameter.

amine resin
synthetic resin derived from the reaction of urea thiourea, melamine, or allied compounds with aldehydes, particularly formaldehyde.

ammonium bichromate (ammonium dichromate)
a compound or salt used for rendering colloids or emulsions active to actinic light such as in photostencils.

ammonium fixer
photography, a fixing bath containing NH₄+ (univalent ion of ammonia) that is used for removing silver halides from photosensitive emulsions.

amp
abbreviation for ampere.

ampere
a standard unit of current produced by one coulomb of charge passing a point in one second.

amphoteric
capable of acting either as an acid or base.

ampule (ampoule)
a small hermetically sealed glass container that is designed to be filled and then sealed by fusion of the glass neck.

amyl acetate
used in some lacquer formulations because of low evaporation rate.

analine printing
refer to flexographic printing.

analogous color
colors that appear next to the primaries on the color wheel; different colors related by having the same base for example blues and purples are analogous.

anamorphic distortion
changing the perceived shape of an object in an image based on mathematically defined criteria.

Analysis of Variance (ANOVA)
the systematic method of statistically evaluating experimental results in order to separate the sources of variation.

anchorage
specific adhesion of an adhesive agent to a face material or anchor coat.

anchor coat (primer) (tie coat)
a coating applied to the face material prior to the application of a pressure sensitive adhesive, to improve bonding (or anchoring) of printed inks.

angel hair
refer to cob webbing.

angle of attack
the angle formed by the face of the moving squeegee blade and the plane of the screen, under pressure. (Due to the flexibility of the blade, this angle generally differs from the squeegee angle, which is measured without movement or pressure).

angle of view
that portion of a subject which is seen by the camera lens, as determined by the focal length of the lens.

angle, squeegee
the angle formed by the face of the squeegee blade, on the side toward the direction of the printing stroke, and the plane of the screen mesh, with squeegee in printing position but without pressure.

angle, screen
the positioning of multicolor halftone screens with respect to all others in the same printing group to avoid moiré patterns.

angstrom
used to express the length of light waves; a standard measure of a lightwave; a unit of length equal to one hundred millionth (10^-8) of a centimeter. (The visible spectrum extends from red light, 7,000 angstrom units, to violet light, which is about 4,000 angstrom units).

aniline dye
synthetic dyestuff made from coal tar or its derivatives.

aniline point
the temperature at which a volume of a hydrocarbon will dissolve an equal volume of aniline oil. (The aniline point is regarded as the temperature at which the mixture becomes homogeneous and is useful in evaluating solvent power).

animation
to make or produce, so as to create the illusion of motion.

anneal
to heat a material to a predetermined temperature and slowly cooling it to relieve stress and make it less brittle, also refer to temper.

anodize
an electrochemical oxidation of aluminum to form a porous aluminum oxide surface, which can be colored and is nonconductive, non-corrosive, and resistant to abrasion.

anodizing
the process of adding a protective oxide film to metal by an electrolytic process.

ANOVA
acroynm for Analysis of Variance.

ANSI
acronym for American National Standards Institute; formerly the American Standard Association.

antiforming agent
ink additive that breaks foaming bubbles that may occur during printing.

antihalation
a coating or backing put on a film or screen mesh to prevent blurring and/or spreading of light by reflection from the film base or threads. (In screen mesh, antihalation is achieved by dyeing the fabric various shades of yellow, orange, or red).

antioxidant
a chemical substance that selectively reacts with oxygen to inhibit or prevent oxidation.

antique finish
a natural or cream color, relatively rough finish on paper stock resulting from the use of long nap felts on the wet presses that are run with light pressure to give bulk, and with little calendering pressure.

anti-aliasing
the removal or softening of image rough edges (jaggies) by averaging or blending of surrounding colors.

anti-skinning agent
chemical substances that retards skin formation on the surface of an oxidizable ink; sometimes referred to as antitoxidants.

anti-static agent
medium which when added to the molding material or applied on the surface of the molded object, make it less conducting.

anti-static solution
any liquid sprayed or otherwise coated onto a surface that tends to prevent or reduce the build up of static electricity.

anvil cut label
pressure sensitive label that have been die cut through components of the label stock.

AP
an abbreviation for artist’s (author’s) proof.

aperture
(1) the open area in screen printing mesh between the threads; (2) opening in a camera lens through which light rays pass from subject to film plane to form an image.

aperture percentage
the percentage of the total area of a web of screen printing mesh that is not occupied by the threads of the weave; i.e., that portion of the fabric area through which ink can pass.

apochromatic lens
a process lens that has been corrected for both chromatic and spherical aberrations.

apparent dot area
percentage of dot coverage in a specific area, as measured using a densitometer and calculated using the Murray-Davies equation.

apparent dot gain
difference between the apparent dot area of the film, as measured by a transmission densitometer, and the apparent dot area of the proof or printed sheet, as measured with a reflection densitometer. (Indicates how much the dots of ink have spread in relation to the original film dot area).

apparent viscosity
a characteristic of multi-component liquids that have a variable ratio of shreds stress over shear rate (variable viscosity depending on conditions).

appearance
manifestation of the nature of objects and materials through visual attributes such as size, shape, color, texture, gloss, transparency, and opacity.

application
(1) an adhesive-coated film emblem, or decal affixed to a designated substrate; (2) an ink or color screen printed directly onto a substrate; (3) often used as a general term to designate a particular screen printed product; (4) the highest level of software that a user sees; also a generic term for software.

application printing (textile)
the placement of coloring agents directly onto the fabric substrate.

application tape (application paper)
a support material used to facilitate the application of pressure sensitive markings.

application temperature
the miniumum temperature at which a pressure sensitive material can be applied to a surface.

applicator
an instrument or equipment for applying something such as a device that automatically feeds and applies labels to the product.

applied color decorating
decorating by applying color directly onto the substrate, as opposed to using transfer or decal techniques.

apron
extension area of lehr for handling of ware, also be applied to extensions of conveyor dryer for stock handling.

aq
abbreviation for aqueous.

AQL
acroynm for acceptable quality level.

aqueous dispersion
pigments dispersed in a water soluble binding medium that changes to a water insoluble form when the printed cloth is steamed or heat cured.

arcing
a spark discharge of electric current crossing a gap between two electrodes.

arc lamp
refer to carbon arc.

arc resistance
the resistance to current flow across the surface of the material measured as the time required for an arc to establish a conductive path in a substance.

archival
Term loosely used to refer to material that can be used without side effects in the conservation or care of important artifacts. Pertaining to the production of new items designed to have very good aging qualities.e.g. non-fading inks, acid free paper, etc.

archival ink
ink used in fine art digital printing that has been optimized for permanance.

archiving
retention of images, often on CD-ROM, for a specified period. Information necessary to reproduce the print is also archived, including ink, tables, sizes, and media used.

argon
a colorless, odorless inert gas.

aromatic solvent
organic liquid derived from products of petroleum origin having a cyclic or ring hydrocarbon structure and KB (Kauri Butanol) value over 40 such as toluene or xylene.

artifact
unwanted visual anomalies or defects generated by an input or output device, or by a software operation, that degrade image quality. See also aliasing, moiré pattern.

artificial fiber
a classification of manufactured fibers made from natural sources such as wood or other plant material.

artificial daylight
man-made light source that closely reproduces the color and spectral distriburion of natural daylight.

artificial fiber
a classification of manufactured fibers made from natural sources such as wood or other plant material.

artist’s proof
prints or serigraphs from an edition that are owned by the artist and generally are not offered for sale. (They are of the same quality as numbered prints in the edition).

art knife
a tool with an usually small, keen blade used for very light cutting of sheet material such as frisket paper, masking film, tracing sheet, and other such materials.

art paper
a coated paper often having a high finish used in printing halftones.

art print
printing of original or reproductions of artwork with any number of methods. Iris/Giclee/Inkjet,lithography, offset lithography, serigraphy being the major sources for Art Print production.

art reproduction
to make a reasonable facsimile of an art object. Could be reproduced in any of a number of methods; painted, inkjet, serigraph, offset lithography, sculpted, cast etc.

art type
type faces, designs, and individual characters screen printed onto gummed acetate sheets. (The type or designs are cut from the acetate sheet and made to adhere to the copy by merely pressing on or rubbing gently), also refer to alphabet sheets.

art work
the original copy intended for reproduction, also refer to rough art and camera ready art.

art work, comprehensive
design produced primarily for customer approval of layout, not necessarily camera ready. (Color work may be indicated by overlays to show color areas over the black and white base design).

art work, separated
art work produced to indicate separation of color areas; a separate layout for each color.

ASA rating
the American Standards Association (US) scale by which the relative sensitivity of photographic films is identified, largely replaced by DIN and ISO rating scales.

ascender
the portion of a lower-case character that extends above the main body such as b,d,or h.

aspect ratio
(1) ratio of length to diameter of a fiber; (2) relationship of an image horizontal length and vertical height, designated with horizontal number first such as 3:2.

ASQ
acronym for American Society of Quality (USA), formally American Society for Quality Control (ASQC).

Association Connecting Electronics Industry
association of companies involved in printed circuit boards and electronic assemblies; refer to IPC.

astigmatism
a relective defect of a lens that prevents focusing of a sharply defined image and from bringing horizontal and vertical lines to a sharp focus at the same time on a flat surface.

ASTM
acronym for American Society for Testing & Materials (US).

atmosphere
(1) climate or environment in a given place, generally a reference to temperature and relative humidity; (2) a standard unit of pressure, equal to 1.01325 x 10⁵ newtons per square meter or 14.7 pounds per square inch or 760 mm of mercury.

atomic absorption tester
laboratory equipment used for detecting the presence and concentration of metals such as lead and cadmium.

attenuation
a decrease in the maximum concentration or total quantity of an applied chemical during a fixed time.

atto
a prefix utilized in the Metric System of Measurement which denotes 10 to the negative power of 18 (10^-18 ) or 0.000 000 000 000 000 001.Its symbol is a.

attribute
(1) a quality or distinguishing characteristic of a sensation, perception, or mode of appearance, distinction is made between chromatic and geometric appearance attributes, colors are often described by their attributes of hue, saturation, or mode of appearance; (2) used in statistical process control (SPC) to denote characteristics that are qualitative.

attributes data
qualitative data that can be counted for recording and analysis purposes.

audiometer
an instrument that measures hearing sensitivity.

automatic conveyorized drying
a widely used means of drying a screen print without racking that incorporates a conveyor belt with a drying or curing chamber.

automatic feeder
a device for picking up single sheets from a pile and moving them, one at a time into the printing area of the press to be printed.

automatic machine (automatic press)
a machine that completes partial or full operation cycles by means of energy other than human motion. (A fully automatic screen press loads, prints, and discharges the print without manual effort on the part of the operator other than the switching on and off of the energy source, usually electricity, or controlling machine speed. In some cases, may include ink feeding).

automatic peel
a feature generally found on a larger automatic screen printing press, where the screen is lifted mechanically behind the moving squeegee, by a spring or cam device.

automatic processor
a unit where exposed photosensitive sheet material is fed to travel through the processing baths under controlled conditions, and be delivered fully processed and dried at the point of removal.

autopositve film
a film that develops a positive form from a positive original on exposure, or a negative image from a negative original by reflex exposure through yellow sheeting.

autoscreen film
film that has a line halftone screen incorporated into the emulsion, and after exposure to an original, develops to a halftone image.

auxiliary display
any type of point-of-purchase display that is in addition to general line of checkout displays, including floor displays, baskets, racks and counter displays.

auxiliary racks
display fixtures that are in addition to general line racks, including checkout racks, and racks that can be attached to a general line rack.

ave
abbreviation for average.

avoirdupois weight
a system of weights and measures based on a pound containing 16 ounces, 7000 grains, or 453.59 grams, and an ounce weighing 16 drams.

AWG
acroynm for American Wire Gauge.

axis
(1) a straight line, real or imaginary that passes through a body and about which the body may or actually does rotate; (2) geometric guidelines used to place a coordinate that determines knife or tool paths for plotters and routers.

azodye
any of various red, brown, or yellow acidic or basic dyes derived from nitrobenzene in an alkaline solution.

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