HueForge and the Free Alternatives: Filament Painting Compared

Filament painting is one of the most striking things a hobby printer can make: a flat print, a few millimetres thick, that looks like a painting or a photo. HueForge made the technique popular, and since then several free tools have appeared that do something similar in the browser.

Quick answer

• Most powerful: HueForge. The desktop app that started it all, with the most control. $24 lifetime for personal use.
• Best free option for Bambu Lab users: MakerLab Chroma Canvas, free in the browser with a MakerWorld account, exports a ready 3MF.
• Best free and open source: Kromacut, with auto-paint and 3MF export.
• Simplest free browser tool: Filament Painter, free for non-commercial use.

How filament painting works

Thin layers of filament let some light through. Print a dark base, then lighter layers on top, and the thickness at each spot decides how much of each colour you see. The software turns your image into a height map and tells you at which layer to switch filament. Every colour you add gives more tones, but also more swaps.

HueForge

HueForge is a desktop app (Windows, Mac and Linux) and the reference for this technique. It has the deepest control over filament choice, layer heights and blending, a large community sharing settings, and it exports an STL with a swap plan (3MF through a plugin). The Personal Use licence is a one-time $24; selling prints needs a commercial licence ($60 a year for Limited Commercial).

If you plan to make many filament paintings, or sell them, HueForge is worth the money.

MakerLab Chroma Canvas

Chroma Canvas is Bambu Lab’s free take on the idea, running inside MakerWorld’s MakerLab. Upload an image, pick a colour palette the way you would pick a photo filter, and download a 3MF that already contains the colour-change plan. Its AI can split the picture into regions, such as subject and background, with a different palette for each. You need a free MakerWorld account.

Kromacut, Filament Painter and ColorStack

Kromacut is free and open source, with an auto-paint mode that picks colours for you and 3MF export.

Filament Painter runs in the browser, is free for non-commercial use, and costs $20 for a commercial licence. It exports STL.

ColorStack has a free tier with STL export, up to 8 colour layers and a daily limit; 3MF export is part of the paid plan. It also makes flat multicolour prints and simple image-to-STL conversions.

When you want a relief instead

Not every image wants to be a painting. For a raised logo, a sign or a plaque, a relief works better:

• ImageToStl converts PNG or JPG into a heightmap or an extruded STL, for free.
• SVG 2 STL takes a vector logo and extrudes it to the height you choose.

Tips for your first filament painting

• Start with 4 colours: black, a dark grey or colour, a light colour, and white.
• Print at 0.08 to 0.12 mm layers for smooth blends. It takes longer, but the result is worth it.
• Keep the base solid: two or three layers of your darkest colour give the picture its contrast.
• Back-light test: hold your first print against a window. If colours look muddy, increase the base layers.

Frequently asked questions

What is filament painting?

Filament painting prints a picture as a thin, flat model where each layer can be a different colour. Because thin layers of filament are slightly see-through, the colours blend and create shading. The result looks like a painted image straight off the build plate.

Do I need a multicolour printer for HueForge-style prints?

No. The colour changes happen at set layer heights, so a single-nozzle printer works if you pause and swap filament by hand. A multicolour unit such as an AMS just makes it automatic.

Is HueForge free?

No. HueForge is a desktop app with a Personal Use lifetime licence of $24 and commercial licences on top. Free alternatives include MakerLab Chroma Canvas, Kromacut and Filament Painter (free for non-commercial use).

Which filament works best?

Matte PLA in a wide range of colours works best, starting with black and white. Each filament has a transmission distance (how see-through it is), and the tools use that value to calculate the blends.