Skip to content
Colorune
How it works

What happens between the photo and the paper.

Generating a drawing is the easy half. Making it survive a home printer is the half that decides whether a seven-year-old can actually colour it in.

Try it now
The same street corner as a printable black and white colouring page
Photograph of a street corner with a bicycle and a cafe awning
Your photoColouring page

Drag the handle — or use the arrow keys — to slide between the original and the line art.

  1. 01

    You give it a subject

    A JPG or PNG you own, up to 12 MB, or a one-line description. Photos where the subject fills the frame and the light is even give the cleanest lines; very dark or cluttered photos produce muddy ones.

  2. 02

    The model draws line art

    An AI image model produces the drawing in the style and detail level you chose. Style changes the character of the line; detail level changes how many separate areas there are to colour.

  3. 03

    We threshold it to true black

    Generated art is full of soft grey edges that print as smudge. Our code flattens every pixel to either pure black or pure white, so a printer lays down one clean line.

  4. 04

    We widen the hairlines

    Strokes thinner than a home inkjet can resolve get dilated until they survive the page. Without this step the fine detail in Zentangle and Mandala simply disappears on paper.

  5. 05

    We lay it out for paper

    The drawing is placed on A4 or US Letter inside a printable margin, so nothing is clipped by your printer's unprintable edge. Any title is typeset here, in a real font.

  6. 06

    You download and print

    PNG on every plan; print-ready PDF on Sketchpad and Colorbook. On Colorbook you can bind many pages into one book PDF.

Two things we deliberately do not let the model do

It never draws text

Image models cannot spell reliably. Any title, date or label on your page is typeset by our code in a real font, after the drawing is finished. That is why Colorune pages never come out with garbled lettering.

It never decides what is allowed

The red lines — copyrighted characters, documents, face swaps, adult content — are checked in code before a request reaches the model, and checked again on our servers. Acceptable use policy.

A wall of finished coloured-in pages pinned up with washi tape

Choosing a detail level

A bold, simple line-art page

Bold & simple

Thicker lines, fewer enclosed areas. Prints well and suits younger hands and thick crayons.

A richly detailed line-art page

Rich detail

Finer lines and many small areas. Suits fineliners, pencils and colourists who want a long session.