Risograph

A Riso is a duplicator, not a printer

The machine burns a stencil — a master — for each colour, wraps it around a drum loaded with one ink, and rolls the paper past it. One drum, one colour, one pass. To print two colours the paper goes through twice.

Almost everything people love about riso follows directly from that. The sheet is fed twice, so the second colour never lands in perfect register with the first, and that slight slip is the look. The ink is soy-based and sits on the surface rather than soaking in, so it stays flat and slightly mottled and will smudge under a thumb. And there is no process black — you get the specific spot inks that shop happens to own, which is why riso work has that palette of fluorescent pink, teal and a particular blue instead of a full gamut.

Separating a photograph into two or three inks

With a fixed set of opaque inks and no black, you cannot separate the way CMYK does. The separation here is by luminance: the tonal range is divided between the inks, each ink gets its own screen, and the screens are multiplied over a tinted paper ground so they darken where they overlap the way real ink does.

Each ink is screened at its own angle — fifteen, forty-five and seventy-five degrees — for the same reason a process press offsets its plates. Two identical screens laid over one another beat into moiré; offsetting them turns that interference into an even rosette instead. Adding the third ink adds a genuine third tonal step rather than just another colour, which is what stops a three-ink riso reading as a duotone with something on top.

Ink Per Plane

Risograph carries the app’s DEPTH PLANES control, and it is the one effect where the planes are not about level of detail. The option is Off or INK PER PLANE, and with it on the separation follows the scene front-to-back instead of following tone: the first ink takes the nearest plane, the last ink the farthest, with a feathered handover between them so nothing hard-edges at the boundary.

The result is a print where the colour separation carries the depth. A figure printed in one ink standing in a ground printed in another is a thing a real riso shop would need two carefully drawn masters to achieve.

When you’d reach for it

Zine, gig-poster and small-press work, and anything that wants to look printed by someone rather than output by something. The constraint reads as a choice, which is exactly what a limited palette is for.

It rewards being given a simple image. A photograph with a clear subject and a lot of open tone separates beautifully into two inks; a busy one turns to mud, in the app for the same reason it would on the machine.

Every option, from the app

Generated from the registry the app publishes, so this list is whatever the current build actually ships — not a copy of it.

Inks

2 inks3 inks

Planes

OffInk Per Plane

Related effects

• HalftoneA real halftone screen — an angled grid of cells whose ink coverage tracks tone, in dot, line, cross or square, with a separate four-colour process screen for CMYK.
• Gradient MapRemap tone through an editable multi-stop gradient baked to a LUT, in RGB or OKLCH — the difference between recolouring an image and tinting it.
• DitherOrdered dithering: Bayer and blue-noise threshold masks quantised to real machine palettes — Game Boy, PICO-8, CGA, EGA, NES, C64, ZX Spectrum and more.

It’s one of the free effects — open the app and it’s there, no signup. Open V3KTR · all the FX · how it works