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3DAI
Free · runs in your browser · images stay on your device

Filament Painting Generator

Filament painting turns a picture into a thin relief printed in 2 to 6 filaments, dark at the bottom and light on top. Thin layers let the colour below show through, so a few swaps give many shades. Upload an image, pick your filaments, then download the STL and the list of layers where you change filament.

Loading the filament painting generator...

How to make a filament painting

  1. 1

    Upload a picture

    Choose a PNG, JPG or WebP with clear light and dark areas: artwork, a landscape, a pet or a logo. It stays in your browser.

  2. 2

    Pick your filaments

    Add 2 to 6 colours from bottom (darkest) to top (lightest), or press Suggest colours. Set each TD value from your filament maker or your own test.

  3. 3

    Set size and layers

    Choose the size, layer height, base and total height. The preview shows roughly how the stacked colours will look, in 2D and in 3D.

  4. 4

    Download and print

    Download the STL and the swap list. Slice with the same first layer and layer height, add a filament change at each listed layer, and print.

What the settings do

Every height is snapped to a layer boundary, so each colour change falls exactly on a layer your slicer prints.

Layer height0.08 mm gives the smoothest colour blends but the longest print; 0.12 mm is a common middle ground; 0.2 mm is fast with fewer shades.
First layerMust match your slicer's first layer height. Every swap height is the first layer plus a whole number of layers.
BaseThe solid plate at the bottom, printed in the first filament. 0.4 to 1 mm is usual; thicker is stiffer.
Total heightThe highest point of the picture. 1.5 to 4 mm is usual. More height means more layers per colour and smoother blends.
TD (transmission distance)How thick a filament must be before you can no longer see what is under it. Low TD (black, about 0.5 mm) covers fast; high TD (white, yellow, 4 mm or more) lets lower colours show through.
Height fromBrightness: light areas high and dark areas low (or the inverse). Colour match: each spot gets the height whose stacked colour looks closest to the picture.

Typical TD values

These are the presets in the tool: rounded, typical values for PLA, not measurements of any brand. TD varies by brand, colour and batch, so measure yours or use the value your filament maker publishes.

ColourTypical TDCovers
Black0.5 mmfast (good base)
Dark grey1 mmfast (good base)
Grey1.5 mmmedium
Light grey2.5 mmmedium
White4 mmslowly (lets colours below show)
Red3 mmmedium
Orange4 mmslowly (lets colours below show)
Yellow6 mmslowly (lets colours below show)
Green4 mmslowly (lets colours below show)
Blue5 mmslowly (lets colours below show)
Brown1.5 mmmedium
Skin / beige3 mmmedium

Turn your artwork into a real 3D model with AI

A filament painting is a flat relief. To get a full 3D figure from the same picture, with an STL ready to slice, use our AI image to 3D generator. The AI generators use credits; this tool does not.

Image to 3D with AI →Photo to STL

Want one colour, lit from behind? Try the lithophane generator.

More free 3D printing tools

Lithophane generatorPNG to STLSTL viewer

Filament painting FAQ

It is a way to print a picture in several colours on a printer with one nozzle. The picture becomes a thin relief, and you change filament at a few layer heights, from dark at the bottom to light on top. Thin areas show the dark colour below, thick areas the light colour on top, which gives many shades from a few filaments.
It does the same basic job for free in your browser: image in, layered relief STL and a filament swap list out, with TD values and a preview. HueForge is a paid desktop app with many more controls and a large filament library. This generator is simpler and quicker for a first print.
TD (transmission distance) is roughly the thickness at which a filament stops letting the colour below show through. Many filament makers publish TD values, and you can measure it with a TD meter or a printed step test. The presets here are typical values only: measure yours, because TD changes by brand, colour and even batch.
Start with 3 or 4: black, one or two greys and white give a clean greyscale picture. Add a colour (for example blue for sky or green for trees) when the picture has a strong colour of its own. More filaments mean more swaps but richer colour. This tool takes 2 to 6.
Use the layer height you set here, exactly, and the same first layer height. 0.08 mm gives the most shades per colour, 0.12 mm is a good balance, and 0.2 mm prints fast with visible banding. Print flat on the bed with 100% infill, ideally with a 0.4 mm nozzle.
Slice the STL, open the layer preview, move to each layer in the swap list and add a filament change (or a pause) there. Most slicers show each layer by its top height, which is the Z value in the list. The printer stops before that layer, you swap the filament, purge and resume. Multi-material units can do the swaps for you.
It is an approximation. It stacks each layer over the one below using its TD value, which is close enough to compare settings, but real prints also depend on light, filament finish and how well each TD value matches your spool. Print a small test before a large piece.
No. The image is read, turned into a height map and meshed in your own browser. Nothing is sent to our servers, and no account is needed.

HueForge is named only for comparison; The3DAI is not affiliated with HueForge or its developer.