Riso Printing /

Riso Printing Guide

Various prints of a dinosaur image

A 3-color print with Sunflower, Bright Red, and Blue inks.

How it works

Riso machines create a stencil (sometimes called a master), similar to a silkscreen, which is repeatedly inked and rolled over pages.

Stencils are made from rice paper, perforated with tiny holes.

Diagram of stencil on riso drum, producing printed output

Spot color

Most color printing is achieved using a four-ink standard process — Cyan, Magenta, Yellow, and Black (CMYK).

With Riso, by contrast, you can choose one or several inks, from a studio’s spot colors. We are a six color studio:

Black Blue Sea Foam Fluo Pink Bright Red Sunflower

Many Riso ink pigments are outside the CMYK gamut — so you can print more vibrant colors than possible with standard process inks.

File Setup

There are two main paradigms for creating digital files:

Grayscale Layers

Output one grayscale file for each ink color.

InDesign layers panel showing sunflower and pink layer

How-to: Create a separate layer for each ink color. Export each separately.

Simple, easy to get started. Can get unwieldy for complex designs.

Grayscale files for sunflower and fluo pink ink, shown alongside Riso printed output

Color Separation

Take a color original (drawing, photograph, etc) and convert it to Riso inks.

How-to:

  • Use an app such as Spectrolite (easiest)
  • Use Photoshop, following a YouTube tutorial.
  • Download a special Riso ink profile from the Color/Shift project for use in Photoshop (highest quality results)

Works great for art, photos, posters, etc, but not suitable for small text

Instantly preview Riso prints & ink colors in our online Instant Proof tool

Try it

File checklist

Always export as PDF files — not JPG or PNG!

  • 600ppi
  • Name files clearly, e.g. “Maria – green.pdf”
  • Set type using InDesign or Illustrator when possible (vector), rather than as an image (raster)
  • No crop marks or registration marks
  • Do not impose zines or books.

Design Considerations

Tints

Lighter shades in grayscale art will be screened — that is, converted into a halftone screen of smaller holes in the stencil. Therefore, you can access different tints of a color.

Trapping

Dot printed without trapping
Without trapping
Dot printed with trapping
With trapping

You can “expand” colors a little bit into their background or borders to account for mis-registration in printing.

Overprinting

Riso inks are semi-transparent, so inks can be printed directly on top of each other.

You can intentionally overprint multiple colors to achieve color mixes.

View our overprinting charts

Animation of 3-color drawing of sunflowers

Gradients & Drop Shadows

Example of an unflattened image with gradient artifacting
Example of image that has been flattened

PDF files with gradients and drop shadows can print with unusual artifacts if not properly flattened.

Inform us if your file contains these elements so we can fix it in Adobe Acrobat before printing.

Advanced: Gradient Noise

If your gradients fail to print as smoothly as expected, you may want to add some noise to randomize the screen pattern:

  • For Photoshop, follow this Add Noise tutorial.
  • For GIMP, go to Filters > Noise > HSV Noise and apply.

Type

For best results, set your type as vectors in software such as Adobe InDesign or Illustrator.

We usually don’t recommend overprinting small type, as mis-registration of the inks can make it hard to read.

Text in blue and pink ink
Mis-registered type
Text in blue ink
Type printed in one color

Dot Screen

Riso offers a choice for the dots of a halftone screen. This is measured in lines-per-inch (LPI).

If you don’t tell us a specific preference in LPI, we’ll use our best judgement.

Image of cat printed with different dot screens

Higher LPI = finer detail.