Multi-Color Printing Techniques

1. Printer reaches a layer or region requiring a different color
2. Current filament retracts back into the AMS
3. New filament feeds through to the extruder
4. The old color is flushed out next to the build plate, away from the print, the nozzle is wiped, then a short prime on the prime tower stabilizes the flow
5. Printing continues with the new color

Method 1: Pre-colored models (easiest)

1. Download a multi-color model from MakerWorld (3MF format, colors included)
2. Open in Bambu Studio. Color assignments load automatically.
3. Match your loaded filament slots to the required colors
4. Slice and print

Method 2: Color paint tool

1. Import any STL model
2. Select the model and open the "Color Painting" tool in the toolbar above the 3D view
3. Choose a filament/color from the list
4. Paint onto the model surface: the paint follows the geometry
5. Use different brush sizes for detail work

Method 3: Multi-part assembly

1. Import all parts of a multi-part model (separate STL files)
2. Right-click → Assemble to group them by position
3. Assign different filaments to different objects
4. Parts need to interlock or align correctly; they print together as one job

Method 4: Height-based color changes

Use the "Height Range Modifier" to change filament at specific Z heights. Select the model, add a height range modifier, assign a different filament. Good for gradient effects or models where a color change at a specific layer makes sense (e.g., a white base with a colored top).

• Tune flushing volumes: Bambu Studio calculates them for each color pair (Flushing Volumes button in the project filaments section); dark-to-light changes need more than light-to-dark. A multiplier of 0.8 to 0.9 saves filament, but run a test print first
• Group color regions: In Bambu Studio, try to minimize the number of color changes per layer. More changes = more purge
• Flush into infill or support: "Flush into objects' infill" sends flush filament into hidden infill (risky with light or transparent colors and few walls); "Flush into objects' support" is on by default and only works with the prime tower enabled; "Flush into this object" turns extra parts on the plate into flush targets
• Consider the model design: Models designed for multi-color printing (where color changes happen between whole layers, not within a layer) generate much less waste

• Use the same material type for all colors: Mixing PLA and PETG in one print causes adhesion and temperature issues. Stick to all-PLA or all-PETG
• Keep color counts practical: 2–4 colors work well. 8+ colors with many per-layer changes generate a lot of flush waste
• Light colors after dark: If going from black to white, you'll need more purge than white to black. Plan your color order
• Keep the filament buffer clean: Every full AMS (not the AMS Lite) connects through a filament buffer in the feed path between AMS and toolhead: on the X1, P1, P2S and X2D it sits on the back of the printer, on the H2 series it is built in (on the H2S in the top cover, with two sliders and two springs). With a full AMS on an A1 series printer, the A1 Series AMS Hub takes its place. There is nothing to switch on, but a sticking slider causes feed errors (see AMS troubleshooting).