Vi3W
LOG INStart free
Skip to content

Guides

Multicolour 3D prints from AI-generated models

STL has no colour. How to go from a textured AI model to a multicolour print: 3MF, colour painting in the slicer, and splitting parts.

Aman PorwalFounder @ Vi3W

3 min read

A pencil sketch of a brass lantern on paper, with the same lantern rising off the page as a solid, lit object

Quick answer

How do you make a multicolour print from an AI-generated model?

STL can't store colour, so use 3MF. Import the model into a slicer that supports colour painting, such as Bambu Studio or PrusaSlicer, and paint regions with your filaments using the generated texture as a guide. Or split the model into parts in Blender, one per colour, and assign each part a filament.

Try VI3W Now

Texture colour isn't print colour

An AI-generated model's colour lives in a texture: an image wrapped around the surface, with smooth gradients and thousands of shades. A multicolour FDM printer has a handful of filaments. Getting from one to the other means reducing the texture to a few colour regions. There's no automatic, perfect conversion; plan for some manual work.

Format: use 3MF

  • STL stores triangles only. No colour.
  • OBJ can reference textures, but slicers generally ignore them for colour printing.
  • 3MF can carry per-object and per-face colour/material assignments, and is the native project format for slicers like Bambu Studio and PrusaSlicer.

Method 1: paint colours in the slicer (simplest)

  1. Export the model from the generator. From Vi3W, export OBJ for the geometry (or GLB, converted to STL/OBJ in Blender; see GLB to STL).
  2. Keep a render or screenshot of the textured model open as a colour reference.
  3. Import into a slicer with colour painting (Bambu Studio's colour painting tool, PrusaSlicer's multi-material painting).
  4. Assign filaments to colours, then paint regions on the model: fill tools, brushes and smart-fill by angle help.
  5. Save as 3MF, slice, and check the preview: colour changes add purge waste and time.

Good for figurines and toys with a few clear colour areas.

Method 2: split into parts in Blender (cleanest edges)

  1. Import the model into Blender.
  2. In Edit Mode, select the faces for one colour region (eyes, clothing, base) and P › Selection to separate them into their own object.
  3. Repeat per colour. Make sure each part is watertight. Make a model watertight.
  4. Export all parts together (as 3MF if your Blender has a 3MF exporter add-on, or as separate STLs/OBJs).
  5. In the slicer, load them as one multi-part object and assign a filament per part.

Good when colour boundaries must be crisp.

Method 3: print in one colour and paint

Still the most common route for figurines, and it gives the most control. Prime and paint as you would a miniature.

Designing for multicolour from the start

  • Fewer, larger colour regions print better than fine patterns.
  • Ask for flat-coloured, stylised designs: "toy-like, flat colours, simple colour blocks". In Vi3W, check the image stage for clean colour areas.
  • Avoid tiny details in different colours (pupils, buttons); they're hard to paint and add colour changes.

Expect trade-offs

  • Every colour change costs filament (purge) and time.
  • Gradients become bands.
  • Painting in the slicer takes practice for organic models.

For the single-colour route, see the AI 3D printing workflow. For Bambu-specific steps, printing an AI model in Bambu Studio.

Want a toy-like model with clean colour blocks? Generate it in Vi3W, then paint the regions in your slicer.

Try VI3W Now

Last reviewed