Screen Printing & Apparel Decoration Industry Terms

ARTWORK, COLOR & SEPARATION

Adobe Illustrator

Industry standard vector drawing and design application used to create scalable typography, logos, and vector spot color separations for garment decoration.

Adobe Photoshop

Pixel-based photo editing software used in screen printing for generating index color separations, CMYK four-color process channels, and simulated process film outputs.

Angle (Halftone Angle)

The orientation angle of halftone dot lines on film, measured in degrees from 0 to 360. Setting proper angles across multi-color process screens prevents optical moiré patterns.

Art Proof

A digital visual mock-up sent to the client showing print size, garment placement, and target Pantone color callouts for written production approval.

Bezier Curve

A mathematically defined curve used in vector graphics applications that scales infinitely without pixelation or resolution loss.

Bitmap

A digital graphic file mapping exact pixel points directly to screen display coordinates.

Bitmap (Raster)

Pixel-dependent artwork that degrades, blurs, or becomes jagged when scaled up beyond its native resolution.

BMP (.bmp)

A standard uncompressed raster graphic file format defined by pixel width and height.

Butt Register (Butt-to-Butt Registration)

Prepress separation alignment where adjacent printed ink colors meet edge to edge with zero overlap, requiring tight press setup and rigid screen tension.

Camera-Ready Art

Complete, high-resolution artwork ready for film output and darkroom screen exposure with zero further graphic design adjustments needed.

Chain Dot

Elliptical halftone dot structure where dots connect end to end, which can create a banding optical effect known as a string of pearls.

Choke

A prepress trapping technique that slightly reduces the boundary dimensions of an underbase or base white layer, allowing top colors to overlap and conceal white edges.

CMYK

Cyan, Magenta, Yellow, and Key (Black). The four translucent process inks used in four-color process printing to reproduce full-color photographic images on light garments.

Color Separations (Seps)

The process of isolating individual ink colors from a multi-color graphic into distinct black-and-white film positives to expose separate printing screens.

Continuous Tone

An image showing unbroken gradients and smooth tonal transitions (like a photograph), requiring halftone dot conversion before screen exposure.

CorelDRAW

A vector graphics suite frequently used in print production for layout, typography, and film separation output.

DCS 2.0

Desktop Color Separation format; an EPS variant used to preserve multi-channel spot color separations between Photoshop and Illustrator separators.

Diffusion Dither

A method of simulating gradient tones using random patterns of identical-sized pixel squares, eliminating regular halftone dot grids.

DPI (Dots Per Inch)

A measure of printer resolution describing how many physical droplets of toner or inkjet fluid a film printer deposits per linear inch.

EPS (.eps)

Encapsulated PostScript; a standard vector file format compatible across cross-platform graphic design and separation software.

FM Printing (Frequency Modulation)

Stochastic screening where tonal values vary by dot frequency and density rather than variable dot diameter.

Font

A digital set of typographical glyphs of a specific weight, style, and typeface design.

Four Color Process

Printing full-spectrum photographic imagery on light apparel using translucent cyan, magenta, yellow, and black halftone screens.

Frequency (LPI)

Halftone line count per linear inch. Governs detail level and dictates necessary mesh count selection.

GIF (.gif)

Graphics Interchange Format; an 8-bit web image format limited to 256 indexed colors.

Halftone

A print technique reproducing continuous tones and color gradients through a regular grid pattern of variable-sized dots.

Halftone Dots

Microscopic geometric ink spots forming simulated tonal gradients on press.

Halftone Dot Types

Geometric profiles of halftone dots. Round dots are standard for general screen printing, while elliptical dots produce smoother midpoint gradient blends.

Index Color Separation

A separation method using a fixed palette of solid spot colors placed in random diffusion dithers to visually simulate complex color artwork without halftones.

JPEG (.jpg)

Joint Photographic Experts Group; a compressed raster image file format widely used for web and digital viewing.

Knockout

Removing underlying ink layers beneath top colors in prepress artwork to eliminate heavy ink build-up on press and maintain a soft garment hand.

Lines Per Inch (LPI)

The frequency gauge for printed halftone lines on film. The screen printing standard rule is using a mesh count roughly 4.5 to 5 times your film LPI.

Masking Film

A dual-layer film featuring a clear polyester backing and a red or amber UV-blocking film layer cut to produce stencils manually.

Numbering

Printing serialized or athletic numbers onto sports uniforms and jerseys using dedicated numbering attachments or paper stencils.

Pantone Matching System (PMS)

A standardized color matching system used globally to formulate and mix exact ink recipes across plastisol and water-based inks, referenced via the Pantone Matching System (PMS) guide.

PDF (.pdf)

Portable Document Format; an open standard for sharing vector and raster layouts across different operating systems and print hardware.

Pixel

The base square display element of a digital raster image.

Positive (Film Positive)

A transparent film sheet with high-density black image areas used to block UV light during darkroom screen exposure.

Print-Ready Art

Digital artwork scaled to true output dimensions, color-separated, trapped, and formatted with registration marks for immediate film printing.

Process Color

Semi-transparent cyan, magenta, yellow, and black inks printed wet-on-wet to build thousands of perceived colors.

Raster

A grid of individual pixels forming an image, resolution-dependent and subject to scaling degradation.

Registration Mark (REG Mark)

Crosshair targets printed on film positives and burned onto screens to allow exact optical alignment between color heads on press.

RGB

Red, Green, Blue; the additive color model of digital screens, requiring conversion to CMYK or spot colors for garment printing.

RIP Software (Raster Image Processor)

Specialized RIP Software that converts digital graphic tones into precise halftone dot patterns and controls ink density on inkjet film printers.

Rubylith

A red masking film that blocks actinic UV wavelengths, used to hand-cut or plotter-cut film positives.

Simulated Process

A separation method using multiple opaque spot color inks and halftones over a white underbase to reproduce complex, photographic imagery on dark garments.

Spot Color

Solid, custom-mixed ink formulas printed through discrete screens rather than blended using four-color process inks.

Stippling

An illustration technique generating shade and depth using clusters of small, uniform dots.

Stochastic Dots

Uniform-sized micro-dots arranged randomly to build tonal variation without moiré interference patterns.

TIFF (.tif)

Tagged Image File Format; a lossless raster graphic format standard for high-resolution prepress color channels.

Tonal Range Compression

Loss of tonal detail in extreme highlights and deep shadows caused by press dot gain and ink spread.

Toner

Electrostatically charged powder fused onto vellum or film media in laser printers.

Trap (Trapping)

Slightly expanding the border perimeter of adjacent colors in prepress to create a 0.5 to 1 point overlap, preventing visible garment gaps during press movement.

Typeface

The cohesive visual styling and artistic design of alphanumeric characters.

Vector Art

Resolution-independent graphic design defined by geometric paths, lines, and anchor points, scaling to any print size without loss of edge crispness.

Vellum

Semi-translucent paper used as an economical alternative to waterproof inkjet film for screen exposure.

DARKROOM & SCREEN PREPARATION

Abraders

Micro-abrasive chemicals used to condition new monofilament screen mesh, creating surface profiles that improve direct emulsion adhesion.

Actinic Light

Specific wavelengths of ultraviolet light (350 to 420 nm) that initiate crosslinking and curing in photo emulsions.

Blockout

A liquid chemical applied to dry screens to fill in pinholes, cover open frame margins, and seal screen edges against ink leakage.

Bridging

The ability of liquid emulsion to span across the open gaps between mesh threads without dipping or scalloping.

Burn (Exposing)

Subjecting an emulsion-coated screen to ultraviolet exposure to crosslink and harden the non-image stencil areas.

Capillary Film

A pre-measured, light-sensitive emulsion film sheet applied to wet mesh using water and capillary action, delivering ultra-consistent stencil thickness.

Coating

Applying uniform layers of liquid direct emulsion across screen mesh using a dual-edge scoop coater.

Computer to Screen (CTS / DTS)

Direct-to-screen production systems that print UV-blocking wax or ink directly onto dry emulsion, eliminating physical film positives and film alignment errors.

Darkroom

A climate-controlled prepress room equipped with UV-safe yellow lighting used to coat, dry, store, and expose screens.

D-Max

Optical density measurement of the dark image areas on a film positive. High D-Max is necessary to completely block UV light during screen exposure.

D-Min

Optical density of the clear film base, which should remain crystal clear to allow maximum UV transmission.

Degreasing

Washing stretched screen mesh with specialized industrial degreasers to remove airborne dust, oils, and chemical residue before applying emulsion.

Dehaze (Haze Remover)

Applying chemical stain removers in the washout booth to strip stubborn ink ghost haze and locked-in emulsion stains from reclaimed mesh.

Delamination

Premature stencil failure where exposed emulsion separates and peels away from the mesh, directly caused by underexposure, poor degreasing, or damp mesh during coating.

Diazo Emulsion

A two-part photo emulsion sensitized by mixing powdered diazo salts, offering high chemical resistance and forgiving exposure latitude.

Direct Liquid Emulsion

Photo-reactive liquid polymer applied directly onto mesh with a scoop coater to form an ink-blocking stencil.

Drying Cabinet

An enclosed, light-tight storage unit circulating warm, dehumidified air to rapidly dry coated screens horizontally with the print side down.

Dual-Cure Emulsion

A hybrid photo emulsion combining diazo sensitizers and photopolymers, balancing sharp edge definition with strong resistance to plastisol and water-based inks.

Dyed Mesh (Yellow Mesh)

Screen mesh fabric tinted yellow to absorb scattered UV light during exposure, eliminating light undercutting and preserving fine halftone detail on high mesh counts.

E.O.M. (Emulsion Over Mesh)

The measured percentage of dry emulsion building past the mesh knuckles on the print side of the screen. Targeting 15% to 25% EOM creates the inkwell required for sharp edges and opaque ink deposits.

Emulsion Remover (Stripper)

A periodic acid-based reclaiming chemical that dissolves and strips crosslinked emulsion stencils out of screen mesh using an Emulsion Remover.

Exposure Calculator (Step Wedge Test)

A specialized transmission target with neutral density filters used to dial in exact exposure times for your darkroom light source and emulsion brand.

Exposure Latitude

The operational window between underexposure and overexposure where an emulsion still develops clean details without pinholing or burning out fine lines.

Exposure Unit

A darkroom machine featuring high-output LED lamps, metal halide bulbs, or fluorescent tubes and a vacuum blanket to pull positive film flat against screen emulsion during exposure, available in professional Exposure Units.

Face Coating

Applying a secondary coat of liquid emulsion to the substrate side of a dry, pre-coated screen to raise EOM thickness for heavier ink deposits.

Ganging

Burning multiple separate graphics onto a single screen frame to save darkroom preparation time and cut screen inventory costs.

Halation

Lateral light scatter across the glass surface during exposure, occurring when poor vacuum contact leaves air pockets between the film positive and the emulsion.

Inkwell

The gasket cavity formed on the substrate side of the screen by dry emulsion rising past the mesh knuckles, controlling ink gasket thickness on the garment.

Light Integrator

An optical sensor system inside an exposure unit that measures cumulative UV light units rather than raw clock seconds, compensating for bulb age and voltage flux.

Light Undercutting

Light deflecting laterally beneath the edges of black positive artwork during exposure, causing pinholes, loss of fine detail, and choked stencil openings.

Lock-In

A darkroom failure where emulsion reacts with dried stencil strippers or solvents, permanently locked into the mesh so the screen cannot be reclaimed.

Mesh Count

The number of woven threads per linear inch of fabric on standard Screens and Frames. Low mesh counts (86 to 110) lay down heavy, opaque ink deposits; mid-range meshes (156 to 198) serve standard apparel spot colors; high mesh counts (230 to 305) hold detailed halftones and thin water-based inks.

Monofilament Mesh

Screen printing fabric woven from single continuous synthetic strands, providing high dimensional stability, consistent ink flow, and easy reclaiming.

Newton (N/cm)

Newtons per centimeter; the engineering unit measuring screen mesh tension using a mechanical or electronic tension meter.

Photopolymer Emulsion (Pure Photopolymer / SBQ)

Pre-sensitized liquid Photopolymer Emulsion formulated with styryl basolium quaternary salts. Cures extremely fast under UV LED exposure units and offers exceptional shelf life.

Pre-Registration Unit (PRU)

A prepress pin-alignment carrier system used to align film positives onto screen frames before exposure, reducing setup time on press.

Proud of the Mesh

Screen printing darkroom terminology describing the emulsion profile extending cleanly past the woven mesh knuckles on the substrate side.

Reclaiming

The step-by-step chemical and pressure-washing sequence used to remove ink, dissolve emulsion stencils, and strip haze from screen mesh so frames can be recoated.

Re-tensionable Frames (Roller Frames)

Mechanical screen frames utilizing rotating roller bars or expanding corner bolts, allowing printers to stretch, tighten, and stabilize mesh to high tension levels without adhesives.

Rz Value

The microscopic roughness profile measurement of the dry stencil surface. Lower Rz ratings indicate a smoother stencil surface that prints crisper lines.

Safelight

UV-filtered yellow lighting installed in darkroom coating, drying, and storage zones to protect photosensitive emulsion against accidental pre-exposure.

Scoop Coater (Coating Trough)

An extruded aluminum reservoir with precision rounded and sharp edges used to apply uniform wet emulsion deposits across screen fabric, available across multiple sizes of Scoop Coaters.

Tension

The tautness of mesh fabric stretched over a frame, measured in N/cm. Proper screen tension (20 to 35 N/cm) ensures clean snap-off, sharp registration, and lower squeegee pressure requirements on press.

Washout Booth

A dedicated poly or stainless steel sink equipped with waterproof backlighting, water supply lines, and chemical filtration systems used for developing stencils and reclaiming screens, found in modern Washout Booths.

INKS & CHEMISTRY

Bleed Resistant Inks (Low-Bleed / LB)

Plastisol inks formulated with dye-blocking chemistry to prevent polyester disperse garment dyes from sublimating into printed ink layers.

Catalyst (Bonding Additive)

A chemical curing agent mixed into ink by weight to promote adhesion on nylon windbreakers, umbrellas, and slick synthetic performance fabrics.

Centipoise (cP)

The standard physical unit of measurement for fluid dynamic viscosity. Higher centipoise ratings denote thicker ink bodies.

Curable Reducer

A viscosity-thinning liquid additive that loosens thick plastisol ink bodies without altering the ultimate cure temperature profile or causing wash-out breakdown.

Discharge Ink

A specialty water-based ink mixed with zinc formaldehyde sulfoxylate (ZFS activator) that chemically strips garment dye out of 100% cotton threads, replacing it with pigment for an ultra-soft hand feel, found in dedicated Discharge Inks.

Extenders

Clear resin bases added to screen inks to build ink volume, soften hand feel, and lower opacity without reducing working viscosity.

Gel Point

The temperature threshold (typically 180 to 240 degrees Fahrenheit) where liquid plastisol ink solidifies into a dry, touch-safe gel under a flash cure unit without reaching full cure.

High Density (HD) Ink

Heavy-bodied specialty plastisol formulated to maintain sharp, vertical 3D profile edges when sheared through thick capillary film or high-EOM stencils.

High Opacity (HO)

Inks loaded with concentrated titanium dioxide or rich color pigments to block underlying dark fabric colors without needing an underbase.

Ink Degrader

A water-soluble solvent chemical applied to screens after printing to dissolve plastisol or water-based inks and prep mesh for stencil stripping.

MSDS / SDS

Safety Data Sheets; required technical documentation detailing chemical compositions, handling precautions, flash points, and safety rules for darkroom chemistry and inks.

On-Press Wash

A fast-evaporating solvent cleaner used to strip ink out of an active screen on press during color changes without softening the water-resistant stencil.

Plastisol Ink

The garment industry standard screen printing ink composed of PVC resin and plasticizer, available across Plastisol Inks. Remains liquid at ambient shop temperatures and cures into a wash-durable film at 320 degrees Fahrenheit.

Puff Additive

A heat-reactive foaming additive mixed into plastisol ink that expands in the conveyor dryer, producing a raised, textured print.

Thixotropic

The rheological property where inks become thinner and fluid under shear force (like mechanical stirring or squeegee passes) and return to a thick gel state when standing at rest.

Viscosity

The internal flow resistance and shear thickness of an ink, directly affecting screen mesh clearing, squeegee pressure needs, and print opacity.

Water-Based Ink

Screen printing inks suspended in water systems that penetrate fabric fibers, yielding a breathable, ultra-soft hand feel after water evaporates and binder resin cures.

PRODUCTION, EQUIPMENT & TECHNIQUES

Conveyor Dryer

An industrial forced-air or infrared heating tunnel with a variable-speed belt used to bring screen printed garments to full cure temperatures, available in production-grade Conveyor Dryers.

Durometer (Squeegee Durometer)

The hardness rating of polyurethane squeegee rubber blades measured on the Shore A scale. Softer blades (60 to 65 duro) lay down heavy ink deposits; standard blades (70 duro) provide universal performance; hard blades (80 to 90 duro) control fine halftone dots and high mesh passes.

Flash Cure Unit

A radiant quartz or infrared heating station positioned on press to gel underbase ink layers in seconds, enabling multi-color printing on dark apparel without color smearing, featured in shop-tested Flash Cure Units.

Flood (Flood Stroke)

The pass of the squeegee or floodbar spreading an even layer of ink across open screen stencil areas before pulling the downward print stroke.

Manual Press

A hand-operated Manual Press featuring rotating print arms and platens where the operator pulls the squeegee by hand.

Micro-Registration

Precision mechanical adjustment knobs on a print head that let printers adjust screen position along the X, Y, and angular axes down to fractions of a millimeter.

Off-Contact

The parallel distance (standard 1/16 to 1/8 inch) between the screen bottom and the garment surface on the platen, ensuring screen mesh snaps free immediately behind the moving squeegee.

Platen (Pallet)

The flat aluminum or wood surface supporting garments on press during printing.

Platen Adhesive (Pallet Tack)

Pressure-sensitive water-based or mist spray adhesive applied to platens to lock garments in place and prevent shifting during multi-color printing.

Print-Flash-Print (PFP)

Printing a base ink layer, gelling it under a flash unit, and rotating the same screen back into place for a second pass to build maximum color opacity.

Snap-Off

The instantaneous springing action of tensioned mesh lifting clear of the garment right behind the passing squeegee, leaving clean ink lines.

Squeegee

A tool consisting of a rigid handle and flexible polyurethane blade used to shear and force ink through open screen mesh openings, selectable across professional Squeegees.

Strike-Off (Test Print)

A sample print run on shop test fabric or pellons to verify color matching, screen registration, and opacity before loading production blanks.

Underbase (Base White)

An initial white ink layer printed and flashed on dark substrates to create a bright foundation, preventing garment color from showing through top ink layers.

Wet-on-Wet Printing

Printing sequential spot colors directly over previous wet ink passes without intermediate flashing, speeding up press cycles and softening print hand.

QUALITY CONTROL, DIAGNOSTICS & TROUBLESHOOTING

Bleeding (Dye Migration)

A print defect where synthetic polyester dyes turn to gas under conveyor heat, sublimate into the printed ink layer, and tint white ink pink or gray.

Colorfastness (Wash Fastness)

The structural integrity of a cured print to resist fading, cracking, or flaking through repeated domestic or industrial wash cycles.

Cracking

Fissures appearing in printed ink when stretched or washed, indicating the plastisol film did not reach its full 320 degree cure threshold all the way through.

Curing

The thermal crosslinking process where ink achieves wash durability (typically reaching 320 degrees Fahrenheit for standard plastisol, or 280 degrees for low-cure formulas).

Dot Gain

The mechanical enlargement of printed halftone dots on garments caused by squeegee pressure, off-contact flex, and ink flow, darkening midtones.

Fibrillation

Unprinted garment fibers breaking through the ink surface during washing, creating a faded or fuzzy appearance mistaken for wash-out.

Fish Eyes

Circular voids appearing in coated emulsion stencils caused by silicone contamination, oil, or airborne lubricants on screen mesh.

Ghost Image (Ghost Haze)

A faint stain of previous artwork remaining on screen mesh after emulsion stripping, removed by applying haze removers.

Moiré

An undesirable optical interference wave pattern created when film halftone dot angles align awkwardly with the woven grid of the screen mesh.

Orange Peel

A bumpy, mottled surface texture on cured ink caused by insufficient off-contact, low mesh tension, or ink clinging to the screen mesh.

Pinhole

A microscopic defect or void in the emulsion stencil allowing stray ink specks to leak onto the printed garment, repaired using blockout.

Sawtoothing

Jagged, stair-stepped edge resolution along printed lines caused by low emulsion thickness (low EOM) failing to bridge across mesh knuckles.

Spot Gun (Spot Cleaning Gun)

A handheld high-pressure electric solvent sprayer used to blow cured plastisol errors, pinholes, or ink smudges out of finished garments.

Stretch Test

A press room physical diagnostic where a printed ink film is pulled gently after cooling. If the ink cracks and fails to snap back, the print is under-cured.

Thermolabel (Temperature Strips)

Single-use thermal test strips placed directly on the ink layer through the conveyor dryer to verify peak cure temperatures.

Underexposure

Insufficient UV light during screen exposure, leaving the emulsion on the squeegee side soft and slimy, which leads to premature stencil breakdown on press.

SUBSTRATES & BUSINESS TERMS

Blanks (Blank Garments)

Unprinted t-shirts, hoodies, totes, or fleece items purchased wholesale for decoration.

Fixed Costs

Print shop overhead expenses (rent, equipment financing, software subscriptions) that remain static regardless of weekly print volume.

Hand (Hand Feel)

The physical tactile texture of cured ink on apparel. Water-based and discharge inks yield a soft hand; heavy plastisol underbases yield a firmer hand.

Profit Margin

The financial percentage of revenue remaining after subtracting garment costs, ink, labor, and shop overhead.

Serigraphy

The fine art historical term for silk screen printing, derived from the Latin 'seri' (silk) and Greek 'graphein' (to write).

Shelf Life

The functional storage timeframe of unmixed or catalyzed emulsions, pallet adhesives, and chemical additives before reactivity degrades.

Substrate

The physical material receiving the screen print, such as cotton tees, fleece hoodies, paper art posters, wood panels, or tote bags.

Variable Costs

Shop expenses directly tied to job volume, including blank garments, ink volume used, emulsion, and shipping boxes.