Multi-color 3D printing sounds like it requires an AMS, an MMU or a toolchanger. For a whole class of models it doesn't: if colors change BETWEEN layers (not within a layer), a plain single-extruder printer does the job with manual filament swaps — and zero purge waste.
How layer-based color changes work
The slicer inserts a pause at a specific layer; the printer parks, you swap the filament, and the print resumes. Every layer below the swap keeps the old color, everything above gets the new one. Photo reliefs, lithophane-style prints, signs, logos and puzzle images are all built exactly this way.
The planning question is WHERE the swaps go. For photo prints, each color needs enough layers to become opaque — white typically needs about four layers at 0.08 mm before it stops looking translucent gray.
AMS vs swaps for photo puzzles
An AMS automates the swap but wastes filament on purging and takes longer. Manual swaps on a photo puzzle mean three short pauses in an evening print — many makers find that easier than cleaning purge poop. The result is identical, because the colors are per-layer either way.
If you do own an AMS, the same project files work: the filament change layers simply map to AMS slots instead of pauses.
Skip the math
Our puzzle generator computes the change layers from your photo automatically — the preview shows exactly which layers each color occupies, and the downloaded Bambu Studio project has the swaps pre-configured. Upload a photo and see your color plan in seconds.