Screen Print Separations
Color separation for the screen — without a several-hundred-dollar plug-in, and without uploading a client's artwork.
Screen printing needs one film per screen, and how you split the artwork decides how many screens you buy and how the print looks. This tool offers six separation modes — color match for spot work, luminosity range, CMYK channel for process, contour fill, outline, and underbase for dark garments — with a halftone screen on each film and a live preview of the whole stack. Trapping is expressed in millimeters at output size rather than in pixels, so a choke or spread means the same physical thing whatever resolution you work at.
Because a separation that looks right on screen can still fail on the platen, the preview models the press: ink spread, edge bite, press variance and registration jitter within the tolerance a shop actually holds. Films export as per-channel grayscale, SVG or PDF with crop marks and registration targets. And all of it runs on your own device — the credit-based separation services you would otherwise pay monthly for all require you to upload a client's artwork to a server to do the same job.
Six separation modes
Color match, luminosity range, CMYK channel, contour fill, outline and underbase — spot or process work, on light or dark garments.
Trapping in real units
Choke and spread in millimeters at output size, not in pixels, so a trap holds its meaning across resolutions — and you can preview it against a shop's registration tolerance.
Press simulation
Ink spread, edge bite, press variance and registration jitter, so what you approve is closer to what comes off the platen than to what left the file.
Nothing leaves your machine
Every separation is computed in your browser. No upload, no credits, no subscription, and no client artwork sitting on someone else's server.
How to use it
- Decide spot or process Flat graphics and logos separate cleanly into spot colors. Photographs and blends need CMYK or simulated process, and cost more screens to print.
- Pick the separation mode Color match holds specific inks; luminosity range suits tonal art; contour and outline are for line work. Try two and compare the film count.
- Set the trap in millimeters Ask your shop what registration tolerance they hold, then trap to it. A trap set in pixels is a trap that changes meaning the moment the output size does.
- Add an underbase for dark garments Generate it last, choke it slightly, and check the preview at the shop's registration jitter before you export the films.
FAQ
What is a color separation?
Screen printing lays one ink per screen, so artwork has to be split into one film per color before anything can be burned. A separation is that split: a set of grayscale films, usually halftoned, that together reproduce the original when printed in register.
How many colors should I separate into?
Fewer than you think. Every color is another screen, another setup and another registration risk, and most shops price by the color. Spot separation into three or four well-chosen inks usually beats a six-color process job on both cost and appearance — simulated process is worth it when the art genuinely needs blends.
Do I need an underbase?
On any garment darker than the lightest ink in your design, yes. The underbase is a white layer printed first so the colors above it read as themselves rather than as tints of the shirt. It is generated here as its own separation, choked slightly so it does not peek out from under the colors.