How to use Risograph Separator

Everything between a picture and a stack of riso plates a print shop will actually accept.

A short guide to getting good results, plus answers to the questions people ask most.

Open the tool

How to use it

  1. 1

    Choose your inks first

    Riso is a spot-color process. Two or three inks chosen well beat five chosen loosely, and the ink set changes every decision after it.

  2. 2

    Separate by ink density, not brightness

    A plate's gray level is how much ink to lay down. Converting by luminance is the classic mistake and it is why prints come back washed out.

  3. 3

    Proof the overprint

    Where two inks overlap you get a third color, and swapping the print order changes it. Check the pairs you rely on before committing.

  4. 4

    Run pre-flight, then export plates

    Clear the coverage cap and the margins, then export one grayscale file per ink at final size. Name them by ink so the shop cannot mix them up.

About this tool

Risograph printing lays one spot ink at a time, at a coarse halftone, on absorbent paper — which means the file you send is not one image but one grayscale plate per ink, and the grayscale on each plate means ink density rather than lightness. Getting that wrong is the most common file-prep mistake in riso, and it is the thing this tool is built around. Choose from 31 measured Riso inks including the fluorescents and metallics, set the paper stock, and separate your artwork into plates with a live proof of what the inks will do together.

Because riso is a physical process with real limits, the tool checks the file against them before you send it: total ink coverage against the cap your shop quotes, the lead-edge band where the roller marks the sheet, and the non-printable margins the machine cannot reach. Each check tells you what is wrong and what to change, and anything the tool cannot verify says so rather than showing you a green tick it has not earned. Plates export as per-channel grayscale PNG, SVG or PDF with crop marks. Nothing is uploaded — your artwork stays on your machine.

Features

31 authentic inks, 6 papers

Measured Riso inks including fluorescent pink and the metallics, on stocks from bright white through cream and newsprint to kraft — each shifting the result the way real paper does.

Overprint proofing with ink order

See what two inks do where they overlap, and what changes when you swap which prints first. The order matters on press and almost no tool models it.

Pre-flight before you send

Coverage caps, the lead-edge roller band and non-printable margins, checked against real shop profiles — with the specific fix named, not just a warning.

Plates a shop can open

Per-channel grayscale PNGs with provenance metadata, plus SVG and PDF separations with crop marks and registration marks — the formats printers ask for.

Frequently asked questions

What is a risograph separation?

A riso machine prints one ink per pass from one drum, so a two-color print needs two files. A separation splits your artwork into one grayscale plate per ink, where the gray level tells the machine how much of that ink to lay down. Send the plates, name the inks, and the shop runs them in sequence.

Why does ink coverage matter?

Riso ink is soy-based and does not fully dry between passes. Too much ink and it offsets onto the back of the next sheet, marks under the roller, or refuses to dry at all. Shops quote a cap — commonly somewhere between 50% and 90% total coverage — and they disagree with each other, which is why the tool checks against a chosen profile rather than one universal number.

Will my print shop accept these files?

The exports are the standard ones — per-channel grayscale files at your chosen size, with crop marks — and the pre-flight runs against profiles built from published shop specifications. But shops genuinely contradict one another on flattening, crop marks and resolution, so their own spec sheet is always the authority. Ask them first and set the profile to match.

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