SCREEN LAB IS LIVE

SCREEN LAB is live in the Toolbox. It picks a mesh count that will actually hold your halftone, and it works out how long to burn the screen off a step wedge test. It's free and there's no account wall, so you can open it and go.

It's a screen printing tool, so DTF and DTG shops can sit this one out. Everyone else, stick around, because the exposure half took some arguing to get right.

Both mesh languages at once

Mesh counts come in two dialects. Datasheets mostly talk threads per inch, and plenty of price lists talk T numbers, so you end up buying 43T while the sheet talks about 110 and doing the conversion in your head while holding a coated screen.

SCREEN LAB just shows both. Every mesh reads as "43T (110)", and a toggle flips which one leads, so you can work in whichever your supplier speaks and the datasheet number is always sitting right there. Same cloth, nothing to convert.

The reference table underneath uses the counts printers actually say out loud. If you own a 156 you'll find a 156, not a 158 that a conversion table rounded into existence.

The mesh picker

Type in your target line count, say whether you're running plastisol, water-based or discharge, and pick how hard you want to push it. You get a recommended mesh count and a working range either side of it.

The ink system moves the number because thickness decides how fine you can go. Plastisol is the thick one so it sits at the coarser end, and thinner inks push through finer mesh, which is why the recommendation climbs when you switch.

There's a reverse lookup too, for when the mesh is already on the frame and the question is what it can hold. Pick your grade off the dropdown, anywhere from 12T through 150T, and you get the LPI range it supports. Mesh divided by five is the safe end, mesh divided by four is you pushing your luck.

The bit we argued about: which guide do you own

Now the exposure half. The calculator won't open until you tell it which step wedge you're holding, which sounds like an annoying extra click. Here's why it's there.

Everyone in screen printing knows the 1.414 number. One step on the wedge is 1.414 times the exposure, two steps is double, and you correct off that. What almost nobody mentions is that 1.414 isn't a property of step wedges. It's a property of step wedges with a 0.15 density increment. Stouffer on their own make 0.05, 0.10, 0.15 and 1.00 versions, and several other vendors publish no increment at all.

So say you own a T3110. Lovely guide, 31 steps, published increment of 0.10. If you run a three step correction on it using the 1.414 everybody quotes, the calculator hands you 2.83 times your test time when the honest answer is 2.00. That's 41.7 percent over. You get a burnt screen, you lose your fine detail, and nothing on the bench tells you why.

That's the whole reason for the question. SCREEN LAB lists sixteen guides by name, plus an option for anything unlisted, and sorts them into four buckets. Verified 0.15 guides run the familiar maths. Guides where the maker publishes a different increment still compute, they just run on the maker's number rather than ours, and the tool tells you which figure it used and why your answer will look different to a mate's. Guides where nobody publishes an increment don't compute, because a step number without an increment is just a number. Products that aren't density wedges at all get refused outright.

That last bucket deserves a word, because it isn't a swipe at anyone. The Chromaline calculators, the KIWO EXPO CHECK, the Ulano ExpoCheck: these are real products that work fine on their own terms. They just don't produce the input this formula takes. The KIWO one runs ten zones from 10 percent to 100 percent of your test exposure, which is a linear scale, so a zone number off it means something completely different to a step on a logarithmic wedge. Feeding it in would give you a confident, wrong answer. We'd rather say no.

And if your guide isn't listed

You're not stuck. There's a way to measure the increment yourself, and it takes two exposures.

Burn a screen at your normal time and note the last solid step. Burn an identical one at exactly double the time and note it again. Count how many steps the solid point moved, call it N, and your multiplier is 2 to the power of 1 over N. Type either number into the tool and the calculator opens up running on your measurement instead of our assumption.

If you want proof it holds up: two steps per doubling works out to 1.414, which is the 0.15 figure exactly, and three steps gives 1.259, which is the 0.10 figure.

Twenty emulsions, and the ones that publish nothing

Under the calculator there's an emulsion picker. Twenty products from the brands you're most likely to be running, and every starting time is transcribed straight off the maker's own datasheet with a link back to the PDF. Nothing is averaged or interpolated, and no gap gets quietly filled in with a guess.

Every time carries its lamp with it, because a starting time without lamp context is worse than useless. Four seconds means one thing under a 5kW metal halide and something else entirely under LED.

Saati are the interesting case. They publish no starting exposures at all for their emulsions. Plenty of tools would quietly slot in a plausible figure there. SCREEN LAB says outright that Saati don't publish times, and then shows you what they do publish, which is a step wedge target: seven solid steps off a film positive, six if you're imaging direct to screen. That's the honest version, and it's more useful anyway.

Tap any single published time and it drops straight into the calculator as your test time. Ranges stay as printed, because choosing where to sit inside a range is your call, not ours.

Every number shows its working

Both halves of the tool carry a "why these settings" panel, collapsed by default so it stays tidy on load. Open it and you get the reasoning behind the recommendation with the sources linked, tagged by whether the claim comes from a manufacturer, from wider community consensus, or from PRINTOOLS Research.

The part we're happiest with is what happens when sources disagree, which they do more than the industry likes to admit. Take dyed mesh. Ulano publish a 1.5 to 2.0 times exposure penalty for it, ScreenPrinting.com say 30 percent longer, and a supplier reckons it's barely noticeable on a tuned LED unit. When that happens the panel gets a SOURCES DISAGREE badge and lays out who says what, instead of picking a winner and presenting it as settled fact. Then it tells you to run the step test on your own gear, which is the real answer.

Don't own a wedge yet?

The calculator stays shut until you have a real guide in your hand, because there's no reading you can substitute for one. Stouffer and Chromaline both make them; grab one through your usual supplier and come back.

A quick word on the free printable exposure calculators floating around. They're good and they'll get you close for nothing. They're time based rather than density based though, which is exactly why they survive a desktop printer, and it means they produce no step number. Different method, not a substitute input for this calculator.

Tell us when we're wrong

There's a REPORT AN ERROR button at the bottom of SCREEN LAB and it's not decoration. If a figure doesn't match the datasheet in your hand, or we've filed your guide in the wrong bucket, hit it and tell us what you're looking at. We'll go back to the source and fix it.

That's the entire point of shipping in beta. Some of this data took a lot of digging to pin down, a few makers publish less than you'd hope, and the people best placed to catch a wrong number are the ones burning screens with it every day.

Open SCREEN LAB