ColorLayers
Preparing artwork for screen printing
Screen printing is the one process ColorLayers finishes end to end today: from an image to a set of films with an underbase, trapping and halftones. Here is the whole path, and what the program takes off your hands.
From an image to films
- Open the imagePNG or JPEG. Physical size and resolution are shown before anything is computed.
- Reduce the ink countA palette is picked from the image, with the area each ink covers, so a redundant one is easy to drop.
- SeparateEvery pixel goes to the ink that represents it most closely, within the tolerance you set.
- UnderbaseThe white base is built automatically and choked by a set amount so it does not show from under the colour.
- TrappingOverlaps between neighbouring inks, sized from the shop profile, for imperfect registration.
- HalftonesLine count, angle and dot shape are set per ink.
- ChecksThin lines, small gaps, isolated dots and undersized halftone dots, marked on the artwork.
- ExportFilms, a preview, an ink map and a report in one archive.
Simulated process: a few inks instead of full colour
The most common kind of separation in screen printing today is simulated process: a photorealistic image reproduced not with four CMYK inks but with a handful of spot inks and halftones. It is how dark garments are printed — spot inks are opaque, so over a white base they hold colour where CMYK would simply sink.
That is what ColorLayers does: it picks spot inks from the image, builds a base under them, lays the halftones and checks what will physically image.
Your shop profile, not general advice
Minimum line, minimum gap, line count, trap width and how many inks go down in one pass are properties of your equipment and mesh, not universal numbers. ColorLayers keeps them as a profile and checks every job against that.
So every warning in the program is about your shop. If you print at 55 and at 120 threads, those are two profiles, and what passes in one will not pass in the other.
An underbase for dark garments
On dark fabric colour inks only hold their tone over a white base. The difficulty is not making the base — it is keeping it from showing around the colour at the first small misregistration on the press.
So the base is built from the same masks as the colours and choked inward by the amount in the profile. How much area is left without a base under it is shown, because choking too hard spoils the print in the other direction.
Halftones: line count, angles, dot shape
On a screen, tone exists only as dots. How many per inch is the line count; the angle they sit at is what decides whether you get moiré; the dot shape changes how tone builds from light to dark.
Dots below the size your mesh can image at all are flagged as a problem — before output rather than after.
What is checked before the film
- Thin lines. Anything below the profile’s minimum line will not hold on the screen.
- Small gaps. A gap narrower than the minimum fills with ink and disappears.
- Isolated dots. Single pixels with no neighbours survive neither exposure nor washout.
- Undersized dots. A halftone dot below the minimum never images, and the highlight simply vanishes.
- Resolution. If the image is too small for the chosen line count, the program says so plainly.
What the program does not do
It does not remove the background for you, it does not draw, and it does not decide how many inks the order is worth. It also does not take vector artwork — convert to raster at print resolution first.
And it does not replace a test print. The preview is a simulation, not an impression: real ink, real mesh and real fabric always have their own opinion.
FAQ
How many inks does a job usually need?
+
Two to eight plus a white base is typical. The limit is your press and the order’s budget rather than the program: the profile holds both the ink count and how many go down in one pass.
What input resolution do I need?
+
300 ppi at the size of the print is the usual mark. Below that, detail starts to fall apart on film at 55–80 LPI; the program says so directly when the image is too small for the line count you chose.
Can I separate a photograph?
+
You can, but a photograph is the hardest case: thousands of shades that cannot be reduced to six or seven inks without loss. Check the preview and the difference figure before you output films.
What do I do about a thin-line warning?
+
Three options: thicken the line in the artwork, raise the line count, or accept the risk deliberately. The decision is recorded and goes into the report, so six months later it reads as a choice rather than an oversight.