Screen Printing Terms: A Plain-Language Glossary

Screen printing has its own language. Printers talk about mesh counts, flash cures and underbases as if everyone knows what they mean. This page explains the screen printing terms you are most likely to hear when ordering custom shirts.

We organised 50 terms into five sections, from making the screen to spotting print problems. Definitions draw on printing education pages and equipment makers, listed at the end.

Screens and stencils

Every colour in a screen print starts as a stencil on a mesh screen. These terms cover how that screen is built and prepared.

• Mesh: The woven material stretched across the printable part of the screen. Ink passes through its open areas.
• Mesh count: The number of threads in one square inch of mesh, measured in both directions.
• Screen tension: How tightly the mesh is stretched on the frame. It is measured in newtons.
• Emulsion: A light-sensitive coating applied to the mesh. Once exposed and rinsed, it becomes the stencil.
• Scoop coater: A long, trough-like tool used to spread liquid emulsion evenly across the mesh.
• Capillary film: Emulsion that comes pre-coated on a film base, applied to the screen instead of liquid emulsion.
• EOM (emulsion over mesh): How much emulsion sits past the mesh threads, compared with the total thickness of mesh and emulsion. It affects how much ink gets through.
• Film positive: A clear film with the artwork printed in dark, solid areas. It blocks light during exposure so those areas stay open.
• Exposure: Using UV light to harden the emulsion everywhere the film positive does not block it. This is done in an exposure unit.
• Washout: Rinsing the screen after exposure. The unhardened emulsion washes away, leaving open areas in the shape of the design.
• Stencil: The finished image area on the screen, made of exposed emulsion, that controls where ink goes.
• Pinholes: Tiny unwanted holes in the stencil. They are filled before printing so stray dots of ink do not land on the shirt.
• Reclaiming: Using chemicals to strip emulsion off a screen after a job so the screen can be used again.
• Ghosting (on a screen): A faint leftover image that stays in the mesh after reclaiming. Printers remove it with a dehazing cleaner.

Screen size limits how big a print can be. We can print with screens up to 23 x 31 inches.

Artwork and separations

Before any screen is made, the artwork is split into colours. These words come up when a printer reviews your design.

• Separations: Splitting a multi-colour design into individual colour layers. Each layer becomes its own screen.
• Spot colour: Printing a design with specific, solid ink colours rather than blending colours out of dots.
• Halftone: Dots of one colour that vary in size to create the look of shading or a grey tone.
• LPI (lines per inch): How many lines of halftone dots fit in an inch. It controls how fine or coarse the dots look.
• Dot gain: When printed dots come out bigger than intended, making areas look darker or heavier.
• Moiré: An unwanted wavy or checkered pattern that can appear when dot angles clash with each other or with the mesh.
• Four-colour process (CMYK): Recreating an image with translucent cyan, magenta, yellow and black inks.
• Simulated process: Using a set of spot colours, often six or more, printed as halftones to imitate a full-colour image.
• Trap: Letting the edges of neighbouring colours overlap slightly so small shifts on press do not leave gaps.
• Choke: A type of trap that shrinks the colour underneath so the top colour covers its edges.
• Butt register: Colours that meet edge to edge without overlapping.

We print up to 4 colours per design, and design help is included. For file tips, see our guide to screen printing artwork requirements.

On the press

This is where ink meets fabric. These terms describe the equipment and the moves a printer makes during a run.

• Carousel: A rotating press with several print heads and platens.
• Platen (or pallet): The flat, solid surface that holds the garment during printing. The two words mean the same thing.
• Tack: The strength of the spray adhesive or platen mask that holds the garment still on the platen.
• Registration: Lining up each screen so every colour lands in the right place relative to the others.
• Micro-registration: Fine mechanical adjustment knobs used to line screens up precisely.
• Off-contact: A small gap between the screen and the garment. The gap is there to improve ink transfer.
• Squeegee: A handled tool with a rubber blade used to push ink through the stencil.
• Durometer: A measure of how hard a squeegee blade is.
• Flood stroke: A light squeegee pass that fills the open stencil with ink before the print.
• Print stroke: The squeegee pass that pushes ink through the screen and onto the garment.
• Underbase: A first layer of ink, usually white, printed under other colours so they stay bright on dark garments.
• Highlight white: White printed last, on top of other colours, to make light areas stand out.
• Flash cure: Heating the ink on press just long enough to gel the top layer, so another colour can print over it. It uses a flash dryer.
• Dwell time: How many seconds the flash dryer sits over the garment.
• Strike-off: A test print run before the full job to check colour and placement.

Inks and finishes

Ink choice changes how a print looks, feels and lasts. For a deeper comparison, read plastisol vs water based ink.

• Plastisol: A PVC-based ink that sits on top of the fabric and makes a tough, washable print. It cures with heat.
• Water-based ink: Ink that uses water as its main carrier and soaks into the fibres for a softer print.
• Discharge ink: Ink that removes the garment's dye and replaces it with colour. It works best on cotton and feels very soft.
• Puff additive: An additive that makes ink rise for a raised, 3D effect.
• Opacity: How well an ink covers the colour of the garment underneath it.
• Hand: How a print feels on the fabric. A “soft hand” means you can barely feel the ink.
• Cure: Heating ink until it fully sets and becomes wash-durable. Vastex gives 320°F as the cure point for plastisol.

Common print problems

Good printers watch for these issues. Knowing the names helps you ask the right questions.

• Bleed (dye migration): When dye from the garment moves into the printed ink and tints it. It shows up most often on polyester.
• Ghosting (on garments): A faint, bleach-like mark caused when chemicals from cured plastisol off-gas into a cotton shirt stacked against it.
• Fibrillation: Small fabric fibres poking up through the ink after washing, giving the print a fuzzy look.

Some glossary words mean different things in different shops. “Ghosting” is a good example, since it can describe a mark on a screen or a mark on a shirt. If a term in a quote is unclear, just ask.

Putting the terms to use

You do not need to memorise any of this to order shirts. But a few terms make conversations quicker.

• Ask about underbase if you are printing light colours on dark garments.
• Ask about hand if you want a print you can barely feel.
• Ask about bleed if your garments are polyester or blends.
• Count your spot colours, since each one needs its own screen.

When you are ready, visit our screen printing page. Our minimum is 10 garments, and we send a full quote before anything is printed. Questions are welcome on our contact page.

Questions people ask

What is the difference between a platen and a pallet?

Nothing. Both words describe the flat surface that holds the garment on the press.

What does mesh count mean for my print?

It is the number of threads per square inch. It is one of the details a printer picks to suit your ink and artwork.

Why do dark shirts need an underbase?

A white underbase gives top colours a light base, so they stay bright.

What is a strike-off?

A test print made before the full run to check colours and placement.

Sources

• Vastex International: Glossary of Terms
• Lawson Screen & Digital Products: Over 100 Common Terms Every Screen Printer Should Know
• ROQ: Screen Printing Glossary, 122 Must-Know Terms
• Bella+Canvas: The Screen Printers’ Dictionary
• ScreenPrinting.com: When To Use Discharge Ink (And When Not To)
• ScreenPrinting.com: Plastisol Ink vs Water Based Ink