Reference

Screen Printing Glossary

Every term a printer runs into, explained in plain English — organized by where you meet it in the workflow. This page grows as the site does. Last synced with all published articles: 2026-10-16.

Screens & Stencil Making

Mesh count: Threads per inch in the screen fabric. Low counts (40–86) lay down heavy ink deposits; high counts (200–355) hold fine detail. — read the guide
Emulsion: Light-sensitive coating on the mesh that hardens under UV light, forming the printing stencil.
Screen tension: How tightly mesh is stretched on the frame, measured in N/cm. Low tension causes blurry prints and registration drift.
Off-contact: The small gap between screen and substrate that lets the mesh snap back after the squeegee passes.
Exposure time: How long the coated screen is exposed to UV light. Under-exposed stencils wash out; over-exposed ones lose detail.
Reclaiming: Stripping emulsion and ink from a used screen so the mesh can be coated and reused.
Thread diameter: The thickness of a single mesh thread, in microns. Thicker threads mean stronger screens but smaller openings for ink to pass. — read the guide
Mesh opening (aperture): The clear square hole between threads — the number that decides which ink particles and detail levels can pass through. — read the guide
Open area: The percentage of the screen that is open holes rather than thread. Higher open area means heavier, smoother ink deposit. — read the guide
Plain weave: The standard over-one-under-one mesh weave — what virtually every screen printing mesh is. — read the guide
EOM (emulsion over mesh): The emulsion thickness built up over the mesh surface. EOM acts as a gasket against the substrate and decides how cleanly edges print. — read the guide
Mesh angle: The angle between mesh threads and the frame. Mesh is often stretched at 22.5° so fine lines never run parallel to threads. — read the guide
Washout: Rinsing the unexposed emulsion out of the screen after exposure, opening the image area. — read the guide
Step wedge (Stouffer scale): A strip of 21 neutral-density gray steps placed on the screen during exposure. Counting how many steps stayed solid tells you whether the exposure was right — and by how much to adjust. — read the guide
Mesh designation (T-number): The European way of labeling mesh: threads per centimeter instead of per inch. A 110 mesh is 43T, 156 is 62T, 230 is 90T — check which system a supplier uses before ordering. — read the guide
Yellow-dyed mesh: Mesh dyed yellow or orange to absorb UV light scatter during exposure, keeping halftone dots and fine detail sharp. Common at higher mesh counts. — read the guide

Inks & Materials

Plastisol: PVC-based garment ink that cures with heat (~320°F/160°C). Opaque, forgiving, the textile industry standard.
UV ink: Ink that cures instantly under ultraviolet light. No VOCs and fast, but demands tight process control.
Solvent-based ink: Ink that dries by solvent evaporation. Excellent adhesion on difficult plastics, but slow and VOC-heavy.
Viscosity: Ink thickness. Too thick prints poorly through mesh; too thin bleeds. Adjusted with thinners within maker limits.
Adhesion promoter: Additive or primer that helps ink bond to low surface energy plastics like PP and PE.
Thinner / retarder: Solvents that reduce viscosity or slow drying, preventing ink from drying in the screen.
Thixotropy: Ink that thins while being sheared (stirred, squeezed) and thickens again at rest. Screen inks are formulated this way on purpose: fluid under the squeegee, stable on the part. — read the guide
Yield value (yield stress): The minimum shear stress that makes an ink start to flow at all. Below it the ink behaves like a solid — this is what keeps a printed dot from slumping. — read the guide
Surface tension: The energy of the ink's surface, in mN/m. The ink must be lower than the substrate's surface energy to wet it; mismatch is a classic cause of fisheyes. — read the guide
Viscoelasticity: Ink is both viscous (flows) and elastic (springs back). The elastic component controls filament length, stringing, and how cleanly the mesh releases. — read the guide
Water-based ink: Garment ink that uses water as its carrier and cures by evaporating it. Soft hand feel and breathable prints, but it can dry in the screen mid-run. — read the guide
Discharge printing: A water-based ink system that bleaches the garment's own dye and replaces it with pigment — the softest possible print on dark shirts, but only on 100% cotton. — read the guide
Pot life: How long a mixed ink stays usable before it thickens or cures in the bucket — typically 4–12 hours for discharge systems once the activator is in. — read the guide
Hand (hand feel): How the cured print feels to the touch. Plastisol sits on the fabric with a noticeable layer; water-based and discharge sink in and feel like dyed cloth. — read the guide
Fineness of grind: The size of the largest pigment particles in the ink, read in microns off a grind gauge. Oversized particles clog mesh openings and scratch squeegees. — read the guide

Equipment & Tools

Squeegee: The rubber blade that pushes ink through the mesh. Hardness (durometer) and angle control ink deposit.
Flood bar: Blade that spreads a thin ink layer over the stencil between prints, keeping the image area filled.
Exposure unit: UV light source used to harden emulsion and create the stencil.
Flash dryer: Heat source that gels ink between colors in multi-color garment printing.
Tension meter: Gauge that measures mesh tension in N/cm. The first tool to reach for when prints go blurry.
Rotational viscometer: Spindle or cone-plate instrument that reads viscosity at a set shear rate. The everyday workhorse for incoming ink checks. — read the guide
Rheometer: Research-grade viscometer that sweeps shear rate and stress, revealing thixotropy, yield value, and viscoelastic behavior a single-point viscometer cannot see. — read the guide
Grind gauge (Hegman gauge): Steel block with a tapered groove; ink is drawn down with a scraper and the depth where particles first show is the fineness reading. — read the guide
Tensiometer: Measures liquid surface tension — by ring, plate, or bubble pressure — in mN/m. — read the guide
Drying time recorder: A stylus travels slowly over a printed track, marking the transitions through dust-dry, tack-free, and hard-dry stages. — read the guide
Pencil hardness tester: A weighted sled drags calibrated pencils across the cured ink; the hardest grade that leaves no scratch is the rating. — read the guide
Xenon arc weathering chamber: Test cabinet whose xenon lamp simulates sunlight; prints are exposed for a defined dose to rate light fastness. — read the guide
Pull-off adhesion tester: A glued dolly is pulled off the cured print; the force at failure gives adhesion in MPa. The quantitative alternative to the cross-hatch test. — read the guide
Profilometer (roughness tester): A stylus traces the printed surface and reports roughness values such as Ra — how smooth the ink film actually is. — read the guide
Spreadometer: A fixed ink volume is pressed between parallel plates; the spread diameter after a set time is the flow reading. — read the guide
Squeegee grinder: The machine that sets blade edge geometry — a hand-held knife can never match its angle accuracy or straightness. — read the guide
Edge radius: The microscopic rounding of a squeegee's cutting edge. A larger radius drags more ink and prints heavier, blurrier deposits. — read the guide
Burr: A tiny rolled-over flap of blade material left by grinding. It must be removed before printing or it streaks the print. — read the guide
Squeegee nick: A small chip or notch in the blade edge that leaves a repeating unprinted line in solid areas. — read the guide
Feeler gauge: A set of calibrated thin blades used with a straightedge to measure how straight (or bowed) a squeegee edge is. — read the guide
10× loupe: A pocket magnifier that turns blade-edge inspection from guesswork by feel into visible defects you can photograph and log. — read the guide
Glass test: The reliable blade-edge check: coat flat glass with an even ink film and pull one light squeegee pass. A good edge wipes clean; every nick or low spot leaves an ink trail. — read the guide
Skirt (grinding skirt): The ragged fringe of burr hanging off a freshly ground blade edge. It holds ink, streaks the print, and can shed mid-run — stripped with two light passes of fine wet sandpaper before the blade goes to press. — read the guide

Printing Process

Registration: Aligning multiple color screens so each color lands exactly in position.
Halftone: Tiny dots of varying size that simulate gradients and photographs with a single ink color.
Durometer: Squeegee blade hardness on the Shore A scale. 60 is soft, 80 is stiff, 70 is the all-rounder.
Curing: The final heat or UV process that makes ink reach full durability. Under-cured ink washes off.
Dot gain: Halftone dots printing larger than intended, darkening the image. Managed via mesh, exposure and pressure.
Leveling: The ink film's ability to flow flat after printing, erasing mesh marks and squeegee trails before drying locks the surface. — read the guide
Snap-off: The mesh peeling away from the printed part just behind the moving squeegee. Snap-off speed affects edge sharpness and mesh marks. — read the guide
Thread grade (S / T / HD): The same mesh count is woven with different thread thicknesses: S (thin, more open area), T (standard, the workhorse), HD (thick, maximum deposit and durability). — read the guide
Theoretical ink volume: The physical upper limit of ink a mesh can carry: V = open area × fabric thickness ÷ 100 (Sefar's formula, in cm³/m²). Real deposits come out lower. — read the guide
Particle clearance: The rule that the mesh opening must be at least 3× the largest pigment or flake particle in the ink. Ignore it and the screen clogs within a few prints. — read the guide
Minimum printable line: The narrowest line a mesh can hold: roughly two thread diameters plus one opening (K = 2d + w). This is why fine detail rules out coarse meshes even when the ink would flow through. — read the guide
Underbase: A white (or gray) first layer printed under colors on dark garments so the top colors stay bright. Counts as an extra color with its own screen and print pass. — read the guide
Print-flash-print (PFP): Printing the same white twice with a flash-cure in between — the standard way to get opacity on dark garments without a heavy, stiff deposit. — read the guide
Flood stroke: Spreading a thin layer of ink over the stencil without pressure between prints. Flooding keeps water-based ink from drying in the open mesh during pauses. — read the guide
Moiré: The unwanted interference pattern that appears when a halftone dot grid clashes with the mesh thread grid. Avoided by rotating the halftone angle off the mesh angle. — read the guide
Ink deposit: The actual thickness of ink a print lays down — decided by mesh opening, thread diameter, squeegee hardness and pressure, not by mesh count alone. — read the guide
Halftone ruling (LPI): How fine a halftone is, in lines per inch. Garment prints typically run 25–45 LPI; paper and decals can exceed 85. — read the guide
Line contact: The mesh touches the substrate only along one thin line under the blade — the entire ink-transfer zone. Anything that widens it (bent blade, excess pressure, worn edge) softens the print. — read the guide
Print angle (squeegee angle): The angle between blade and printing surface during the stroke — roughly 20–70° on flat work, 30–65° on curved work. Steeper blade, thinner and sharper deposit; laid-back blade, heavier deposit but more blade bend. — read the guide
Squeegee skew: The small 6–8° offset of the blade's length from square-on to the stroke. A dead-square blade shears ink poorly, traps air in the mesh, and judders on automatics; too much skew plows ink sideways. — read the guide
Peel-off point: The spot a few millimeters behind the moving blade where the mesh actually releases from the wet ink film. If it lags or sticks, prints show smearing, ghosting, or spots — cured by tension, off-contact, and ink condition, not by pushing harder. — read the guide

Quality & Defects

Cross-hatch test: Adhesion test: cut a grid through the ink, apply tape, pull. Rated 0B–5B by how much ink lifts.
Pinholes: Tiny unprinted dots in solid areas, usually from dust in emulsion or under-exposure.
Screen clogging: Ink drying in the mesh and blocking the image area. Common with fast-drying solvent inks.
Ghosting / haze: Faint image stain left in mesh after reclaiming, from ink or emulsion residue.
Fibrillation: Garment fibers poking through the ink film after washing, making prints look faded.
Sawtoothing: Jagged print edges when mesh threads distort fine lines. Fixed with higher mesh counts or thread angle. — read the guide
Bleeding / feathering: Ink spreading past the intended edge in fine hairs, usually from too-thin ink, excess pressure, or poor stencil contact. — read the guide
Fisheyes: Small round craters where ink refused to wet the substrate — classic sign of surface contamination or a surface-energy mismatch. — read the guide
Misregistration: Colors of a multi-color job landing offset from each other; caught first on the register marks, then as fringes or doubled edges on the part. — read the guide
Mesh marks / orange peel: The dried ink surface keeps the mesh's imprint instead of leveling flat — a pebbled texture visible under raking light. — read the guide
Light fastness: How well a print resists fading under light exposure, rated by accelerated xenon-arc testing against blue-wool references. — read the guide
Pencil hardness: Cured-film hardness rated by the hardest pencil grade that does not scratch it — 6B softest through 9H hardest. — read the guide

Business & Industry

FAI (First Article Inspection): Full verification of the first production piece before a run starts. Standard practice in automotive supply chains.
MOQ: Minimum order quantity a supplier will accept.
PPAP: Production Part Approval Process — the documentation package automotive customers require before mass production.
Color matching (Pantone): Mixing or verifying ink color against a standardized swatch system under controlled lighting.
Cost-plus pricing: Setting your price from your own costs plus a markup, rather than copying competitors. The only method that survives a rising rent or blank-garment bill. — read the guide
Markup vs margin: Markup is added on top of cost; margin is the share of the final price. A 40% markup is only a 28.6% margin — mixing the two undercharges by 16%. — read the guide
Quantity break: A lower per-piece price at higher quantities, reflecting how fixed costs (screens, setup) spread over more pieces. Quoting three tiers nudges customers to order more. — read the guide
Spoilage allowance: The misprint percentage (typically 1–3%) built into your per-piece cost so a ruined blank doesn't come out of your pocket. — read the guide
Setup fee (screen fee): The per-color charge covering screen making and press setup — usually $20–40 per screen, quoted either as a visible line or folded into the piece price. — read the guide
Overhead: The costs that exist whether you print or not — rent, utilities, insurance, equipment payments — divided over your monthly piece count to get a per-shirt share. — read the guide