Screens: Frame, Mesh and the Number That Matters
A screen is a frame with fabric stretched tight across it. The frame is wood or aluminium. Wood is cheaper, warps when it gets wet often enough, and is perfectly serviceable for years of occasional use. Aluminium stays flat and is what any studio printing regularly ends up buying.
The mesh is the part worth understanding. It is polyester monofilament, and it is sold by thread count: threads per inch in the UK and US, threads per centimetre in most of Europe. The number decides how much ink gets through.
- Around 43T / 110 threads per inch. Coarse. Heavy ink deposit. Standard for textile work and for opaque white on dark fabric.
- Around 54–61T / 140–156. The general-purpose range. Fine enough for reasonable detail, open enough for most inks.
- Around 90–120T / 230–305. Fine. Thin deposit, holds small type and halftone dots, clogs quickly if the ink is too thick.
Coarse mesh with a fine design gives ragged edges. Fine mesh with a heavy textile ink gives a screen that blocks halfway through the run. Most beginner frustration with screen printing equipment traces back to one of those two mismatches rather than to technique.
Screens have to be tight. Slack mesh touches the substrate before the squeegee arrives, and the print smears. Tap a properly tensioned screen and it sounds like a drum.
Coarse mesh for heavy ink, fine mesh for fine detail, and a written recipe for every colour.
Screen Printing Inks: Four Families and What They Stick To
Ink choice follows the substrate, not preference. Ink for screen printing is sold in families that are not interchangeable, and picking the wrong family wastes more material than any other equipment decision.
Water-based inks soak into fabric and dry soft, with almost no hand-feel on a T-shirt. They air dry, they wash out of screens with water, and they will also dry in the mesh during a long run if the studio is warm. Permanence on textiles needs heat curing.
Plastisol inks sit on top of the fabric instead of soaking in, give a strong opaque layer on dark cloth, and will not dry in the screen at all. They also will not dry anywhere else without heat: plastisol has to be cured at around 160°C, which means a heat press or a conveyor dryer.
Acrylic and solvent-based inks cover the non-textile work. Paper, board, wood, glass, metal, plastic each have their own formulations, and the useful question at the counter is always what surface the ink has to key to.
Speciality screen printing inks are the reason many jobs are screen printed at all. Metallics with real particles, fluorescents, glow pigments, puff inks that rise under heat. None of them have a digital equivalent.
Mixing matters as much as buying. Screen printing inks are mixed as physical colour, which is why a studio can hit an exact brand colour that a four-colour process can only approximate. Keep the recipe written down; matching a mixed colour from memory six months later does not work.
The Squeegee: Durometer, Edge, Width
A squeegee is a rubber or polyurethane blade in a handle, and it is the only piece of screen printing equipment that the printer’s hands directly control. Three properties matter.
Hardness, measured in durometer. Soft blades around 60 flex under pressure and push more ink through, which suits textiles. Hard blades around 80 stay rigid and lay a thin, sharp deposit, which suits paper and fine detail. Around 70 is the general-purpose middle.
Edge profile. A square edge is the default. A rounded edge floods more ink; a bevelled edge prints thinner. Most studios own one square blade and discover the others later.
Width. The blade should be wider than the image and narrower than the screen’s inside dimension. Too narrow and the image needs two overlapping strokes, which never quite match.
A nicked blade prints a line down every copy. Squeegees get sharpened, and a printer who cannot work out why a stripe keeps appearing should look at the rubber before anything else.
Emulsion, Exposure and the Rest of the Screen Printing Equipment List
Emulsion is the light-sensitive coating that becomes the stencil. Two families: diazo, which is mixed with a sensitiser before use and has a working life of weeks once mixed, and pre-sensitised photopolymer, which is ready from the tub and exposes considerably faster. Photopolymer is more expensive and easier to live with.
It is applied with a scoop coater, a trough with a smooth metal lip, in even passes on both sides of the mesh. This has to happen under yellow or red light, because room light is already exposing it. The coated screen then dries flat in the dark.
The exposure source is the piece people improvise for longest and regret improvising. A dedicated UV unit gives a repeatable time. A halogen work lamp at a measured distance works. Sunlight works and is impossible to repeat, because the correct exposure changes with the season, the hour and the cloud. Whatever the source, the first job on a new setup is a test strip: expose a screen in timed bands, wash it out, and read off which band held detail without going soft. That number then holds for every screen of the same mesh and coating thickness.
Emulsion remover and a degreaser finish the screen printing equipment list. Degreasing a new screen before the first coat is the step most often skipped, and skipping it is why emulsion lifts off mid-wash-out.
Frequently Asked Questions
What screen printing equipment do you need to start?
Two screens, a squeegee, emulsion with a scoop coater, a light source, ink for the substrate, and somewhere dark to dry a coated screen. A press is optional. A tabletop and a pair of hinge clamps do the same job more slowly.
Which mesh count should a first screen be?
Around 43T or 110 threads per inch for fabric, around 61T or 156 for paper and general work. Buying one of each covers most of what a new studio will print in its first year.
What squeegee hardness is best for beginners?
A 70 durometer blade. It is soft enough for fabric and firm enough for paper, so one squeegee covers both while you find out which side of the work you prefer.
How long does screen printing emulsion last?
Unmixed photopolymer keeps for around a year in a cool dark place. Diazo, once the sensitiser is mixed in, keeps for a few weeks. A coated screen that has not been exposed should be used within a few days, since it slowly hardens on its own.
Can water-based and plastisol inks be used on the same screen?
Yes, but not in the same session, and the screen has to be properly cleaned between them. The emulsion has to suit both: some emulsions break down under solvent-based cleaning, and the tub states which.
Why does the print come out blurred at the edges?
Usually the screen is touching the substrate before the squeegee reaches it. The screen should sit a couple of millimetres clear and be pressed into contact only by the blade as it passes. That gap is called off-contact, and it is the most common thing missing from a home setup.