Free online color separation for screen printing

What "free" means here, precisely

Spot separation and index separation are free, forever, with no account. Ink count and tolerance, merging and renaming inks, reordering the print sequence, per-plate preview, the proof over your garment colour, manual cleanup, and export to per-ink PNG, ZIP or ORA — unlimited, full resolution, never watermarked. Both PSD exports are free too, and this is the part worth noticing: a layered PSD with one named layer per ink, and a multichannel PSD carrying one real Photoshop spot channel per ink with its ink colour and name attached — the file a RIP and a separator actually expect. Three PSD exports a day on the free tier, uncapped once you hold credits; quantity is capped, quality never is. All of that runs client-side, which is why it can be free: it costs us nothing because it runs on your machine, and it makes no network call at all, so your customer's artwork is never uploaded and never leaves the building. The paid half is the print-ready render, and it is print maths at output resolution: halftone screening at non-moiré angles, a choked underbase, a separate highlight white, per-ink choke and spread, trapping, dot-gain compensation, registration marks, 1-bit film per plate at 600 or 1200 dpi, vector plates, and CMYK and simulated-process separation. That genuinely needs a server, because a 14-inch plate at 1200 dpi is a 16,800-pixel image and that is not a browser job. It is 10 credits per image, and for 24 hours after that render you can re-render the same image as often as you like, free, for 24 hours. Nothing is crippled to sell you the upgrade; the free half is the free half because of where the code runs.

What color separation actually requires

Every ink in a screen print needs its own screen, which means your flat design has to be split into one artwork layer per color: every pixel of that color on one plate, no matter where it appears in the design. Traditionally that means Photoshop channel gymnastics, or dedicated desktop software. The established options are all installs: Separation Studio NXT is a standalone Windows/Mac application on a yearly subscription, while UltraSeps and T-Seps are Photoshop plug-ins bought outright, which means a full Photoshop licence underneath them. They are good tools and they earn their keep in a shop doing daily simulated process work. But they are also a purchase, an install, and a computer capable of running Photoshop — before you have separated anything at all.

One button: Split by color

Layersmith reads your design, finds the distinct ink colors, and lifts each one onto its own layer — named by its hex color, so your layer panel reads like a screen list. And it groups by color, not by connected shape: every letter of your cream lettering, both snowcaps, and every scattered highlight of the same ink land together on one plate, exactly as they will share one screen. One behaviour to know: the free engine keeps the largest colour area as the base rather than cutting a screen for it, on the assumption that the biggest flat field is the garment. On flat art that is right; on a photograph, check what landed in the base before you trust the plate count.

A four-color job, separated

Below is a worked example, and it is real output from the editor this page links to rather than a mock-up: a four-ink retro design on a black garment, separated in one pass in the browser with nothing uploaded. It came back as five layers — four ink plates plus the garment base — at #f6a236 orange, #2e6ea6 blue, #ea4e5e red, #f1ede2 cream, over #121216 garment black. The cream plate is the one to look at: the lettering and both snowcaps share a single screen despite being a dozen disconnected shapes, which is exactly what a separator has to get right and what shape-based tools get wrong. The plates below are PNGs, not JPEGs, because a lossy plate is not a plate.

And the multichannel PSD, checked by something that is not us

The free browser export was read back with psd-tools, an independent open-source PSD reader, and it contains four real spot channels — one per ink, named by its hex, which the reader returned as exactly #f6a236, #2e6ea6, #ea4e5e and #f1ede2 — in colour mode 7 (multichannel), 8-bit, RLE compressed, carrying image resources 1005, 1006, 1077 and 1060. The garment base is deliberately not in it, because the substrate is not a screen and nobody should burn one for the shirt. What we are not going to tell you is that Photoshop has opened it: that test has not been done yet, and until it has, "validated by independent readers" is the only claim we are entitled to make.

Export the way your RIP expects

Three shapes of file, all written in your browser. A layered PSD: one named layer per ink, every plate at full canvas size and in register. A multichannel PSD: one real Photoshop spot channel per ink, each carrying its ink colour and name, at the physical DPI implied by the print width you set — this is the file that behaves like a separation in Photoshop rather than a stack of pictures, and the garment base is deliberately left out of it so nobody burns a screen for the shirt. Or a ZIP of per-ink transparent PNGs, numbered in stacking order. All of it opens in Photoshop, CorelDRAW workflows, Photopea and GIMP. Your film output or DTS workflow continues exactly as before; the part that changes is the hour you used to spend making the seps.

Halftones, underbase and simulated process

These are no longer roadmap items. The Color separation tab handles all four separation types — spot, index, CMYK, and simulated process — and the print-ready render adds the print math on top: halftone screening at non-moiré angles (your choice of frequency, dot shape, and output DPI), a choked underbase, a separate highlight white printed last, per-ink choke and spread, trapping, a dot-gain compensation curve, registration marks, and optional vector-traced plates. Output defaults to continuous-tone grayscale plates, which is what most RIPs actually want; pre-halftoned 1-bit film is a switch away.

Simulated process ships with manual override

Simulated process ships with per-channel curve and density override, and that is deliberate. Fully automatic sim-process is unreliable in every tool on the market — the established desktop packages all keep manual channel control for exactly this reason: Separation Studio NXT at $229 a year, T-Seps at $345 and UltraSeps at $399 (all vendor-listed, checked 28 July 2026), and the newer AI-branded ones do too. A photograph that separates itself perfectly with nobody touching a channel does not exist. So the auto pass is a starting point and then there are the sliders to fix it: pull a channel back, push the underbase, retime the highlight white. If you have never separated a photograph before, expect to make judgement calls; if you have, you already knew that.

Priced against what separations actually cost you

The alternative most shops use for the awkward jobs is an outside separator, and those are per-design fees. Published prices, checked 28 July 2026: ContractPrinter lists $15 for one or two spot colours, $30 for three to five, $55 for six to eight, and $85 and up for nine-plus or photorealistic simulated process, with $5 for each revision; Victory Screen Factory lists $18.99 for two colours rising to $78.99 for eight. That $85 is the top of the field rather than the going rate for photographic work, and it is worth knowing the flat-fee services exist: checked 29 July 2026, Burn My Screen lists a flat $60 per design, 24 Hour Seps — Scott Fresener's own service — lists a flat $65 per set for any number of colours (a promotional rate when checked; their volume packs go lower), and Color-Separation.com lists $15 to $50 including the underbase and highlight white. So realistically, outsourcing a hard sim-process design runs somewhere in the $50 to $85 band, and a simple two-colour job runs $15 to $19. Turnaround field-wide is commonly a day, sometimes two, though neither ContractPrinter nor Victory publishes one. Here, spot and index separation cost nothing at all, and the print-ready render is 10 credits per image, with free re-renders of that image for 24 hours instead of a revision fee and a fresh wait. Credits come with a monthly plan, or as a one-off pack whose credits never expire — see the pricing page for current prices in your currency. For a genuinely difficult photograph on a dark garment, a skilled human separator is still worth the money; for the everyday spot-colour job list, paying per design is overhead you can stop.