Filament painting maker

A filament painting is a flat print that shows a picture through stacked filament colours. The model is a thin relief: dark parts of the picture are low, bright parts are tall. It prints in a few filaments, dark at the bottom and light on top, with a filament change at set heights. Thin plastic lets the colour below show through, so where the light filament is thin you see a mix, and where it is thick you see the light colour alone. From a step back, those layers read as shades. The technique was made popular by HueForge, a paid desktop program; this tool does the same job free in your browser.

1. Drop a photo or picture above. It's read on your device, not uploaded.
2. Pick your filaments, bottom to top: black, grey and white is the classic start. Each has a TD (transmission distance), how thick it must be before the colour under it stops showing.
3. Check How it looks, the simulated print. Move the heights where each filament starts, the brightness and the contrast until it reads well.
4. Download the STL and the change list for a printer with one nozzle, or the 3MF, which has a separate part for each filament, for an AMS or other multi-material printer.

• Use the same layer heights as the tool (0.16 mm first layer, then 0.08 mm by default). The change heights sit exactly on layer boundaries, and a different layer height moves them.
• One nozzle: add a filament change (or a pause) at each height in the list. Bambu Studio, PrusaSlicer and OrcaSlicer do this on the layer slider, and Cura has a Filament Change post-processing script. Each layer prints in one filament, so it's only a few swaps.
• AMS or multi-material: open the 3MF, keep the parts together as one object and give each part its filament. Each part sits at its own heights, so every layer still uses one filament.
• 100% infill, flat on the bed, picture side up. Don't scale the height in the slicer.

• Pictures with clear light and dark work best: portraits with good lighting, pets, landscapes with sky, line art. Low-contrast photos come out muddy; raise the contrast.
• Measure your own TD for the closest match. The values given are typical starting points; two white spools can differ a lot.
• More filaments, more shades. Three gives a good grey picture; adding a colour (a skin tone, a sky blue) between dark and light tints that band of the picture.
• Bigger is clearer. 100–200 mm wide shows far more than a 50 mm coaster.

Want the photo to glow instead, lit from behind? Make a lithophane. For a logo or drawing with flat colours, Image to STL traces clean outlines.