Multi-colour and multi-material
Compare colour swaps and separate tools, estimate purge waste and check material compatibility.
From observation to a working decision
Several colours can share one polymer; several polymers may need very different conditions. A colour changer feeds a shared nozzle, while a toolchanger picks a separate tool. Compare the process before choosing settings.
Try the experiment
Compare changes within every layer with a single change at a height. Estimate a shared purge budget and divide it among copies. The two colours in the model are both PLA.
Your task
Keep purge per copy at or below 0.10 g using at least two copies. Explain how fewer changes or sharing a plate helped; do not lower real purge settings based on this model.
Simplified teaching model. Dimensions and colours highlight the idea; they are not a printer calibration or measured prediction. Orbit changes your view, not the print orientation.
Useful part
Two PLA colours represent a layer-height swap or colours within each layer.
Total purge
8.928 g
Purge per copy
8.928 g
Keep experimenting: the target is not met yet.
PLA density assumed: 1.24 g/cm³. The calculator counts purge only; use the slicer for total tower, travel, priming and print costs.
Shared nozzle versus separate tools
A shared nozzle retains some previous material, so colour changes need flushing. Separate nozzles reduce that mixing but still need priming, ooze management and alignment. The calculator uses your assumed purge volume, not a universal tower size.
Compatibility before appearance
Check nozzle/bed temperatures, adhesion between polymers, drying and the machine feed path. Different materials do not necessarily bond. Flexible filament may be unsuitable for a particular feeder. Use the exact printer and material compatibility guide.
Read the whole preview
A colour change only at one height can require fewer transitions than two colours in every layer. Multiple copies can share one purge schedule. Check tower clearance and the full slicer estimate; tower structure, priming, supports and travel add costs beyond this simple purge model.
Recognize it in the workshop
Terms to keep
- Purge volume
- Material flushed during a transition, measured here in mm³.
- Prime tower
- A sacrificial structure used to establish steady flow.
- Toolchanger
- A system that picks separate print tools.
Use it on your next print
Slice a two-colour badge in two orientations. Compare the transition count, total filament and time. Check the manufacturer compatibility chart before replacing one colour with another polymer.
Check yourself
Pick an answer for each question.
1. Two colours of PLA automatically mean two different polymers?
2. Why can several copies reduce purge per part?
3. What should you check before combining polymers?
Sources (3)
- Wipe tower and shared purge · Prusa Knowledge Base
- Combining materials on separate tools · Prusa Knowledge Base
- SuperBlobMonster — CC BY-SA 3.0 (reference photograph) · Wikimedia Commons
Figures such as temperatures and drying times are typical ranges. Always check the label on your own spool and your printer manufacturer's guidance.