Skip to content

Multi-Material

Printing more than one colour or material in a single job — the hardware that does it, how much filament it wastes, how to reduce that waste, and which material pairs make good break-away or soluble supports.

Types of multi-material systems

There are three basic approaches. Which one a printer uses decides how fast colour changes are and how much plastic goes in the bin.

Category How it works Change time Waste per change Examples
Single-nozzle filament switcher One hotend; a unit unloads one filament and loads the next, then purges the old colour out of the nozzle Slow (tens of seconds to minutes) High — every change purges Bambu AMS family, Prusa MMU3, Creality CFS, Anycubic ACE Pro
Tool changer Several complete hotends/nozzles; the printer parks one and picks up another, each stays loaded and warm Fast (seconds) Low — small prime only Prusa XL, Bondtech INDX (for Prusa CORE One), Snapmaker U1
Dual nozzle / IDEX Two nozzles on one carriage, or two independent carriages (IDEX) Fast Low between the two nozzles Bambu H2D (two nozzles on one head); IDEX machines from several brands

Hybrids exist: a dual-nozzle printer with filament switchers on each nozzle only purges when a nozzle changes within its own set of filaments.

The systems in brief

System Category Capacity Notes
Bambu AMS (original) Switcher 4 slots per unit; up to 4 units (16) on most models Enclosed, desiccant; no active drying.
Bambu AMS 2 Pro Switcher 4 slots; chainable Adds active drying. Works with H2, P2S, X1/P1 and A1 series (adapters/power supply may be needed).
Bambu AMS HT Switcher 1 slot Single-spool unit with drying for high-temperature filaments; chain several.
Bambu AMS lite Switcher 4 slots, one unit only A1 / A1 mini only; open-air spool holders.
Prusa MMU3 Switcher 5 filaments Add-on for MK4/S and MK3.9/S (and older MK3S kits).
Prusa XL Tool changer Up to 5 toolheads Each head has its own extruder, hotend and nozzle; parked heads stay preheated.
Bondtech INDX Tool changer 4- or 8-tool kits Upgrade for the Prusa CORE One: one active "smart head" with induction heating picks up passive tools (nozzle + filament path).
Creality CFS Switcher 4 slots; up to 4 units (16) RFID filament recognition. For Creality K2-series printers; no TPU or PVA/BVOH.
Anycubic ACE Pro Switcher 4 colours per unit Drying up to 55 °C; for Kobra 3 / Kobra S1 series. 8 colours needs two units plus a hub.
Snapmaker U1 Tool changer 4 toolheads Whole-toolhead swap in about 5 s (vendor figure); 270 × 270 × 270 mm.

Check compatibility before buying

Vendors add printer support and change chaining limits with firmware updates, and retailers often disagree. Confirm on the manufacturer's current compatibility page. Switchers generally reject soft TPU and wet/brittle filament (PVA, BVOH, some CF grades) — check the unit's filament list.

Purge & waste

On a single-nozzle switcher, the old colour has to be pushed out of the hotend before the new one looks clean. That purge goes somewhere:

  • Purge chute ("poop") — extruded behind the bed and discarded (Bambu).
  • Prime / wipe tower — a sacrificial tower printed beside the part; also stabilises flow before returning to the model.
  • Into infill — purged material becomes the part's infill (invisible, but can show through thin light walls).
  • Into supports or a sacrificial object — purge into something you'll throw away or don't care about the colour of.

How much? It depends on the colour pair. Prusa's example purge volumes are 150 mm³ for black → white but only 50 mm³ for white → black. A University of Northern British Columbia test of a 4-colour cube on a Bambu printer used 11.4 g of model filament and 79.6 g of flush across 153 changes — roughly 0.5 g per change, and seven times the model itself. CNC Kitchen's two-colour test on a dual-nozzle H2D used 40 g against 129 g for the same print on a single nozzle with AMS.

Reducing waste

  • Batch identical parts on one plate — the number of changes per layer stays the same, so the purge is shared across all copies.
  • Fewer layers with changes: a larger layer height means fewer changes; colours confined to a few layers (logos on the top or bottom) cost little.
  • Orient so changes happen low — the prime tower can stop early. Bambu's wiki shows a ~40 % smaller tower just from flipping a model.
  • Flush into infill / supports / object (Bambu Studio and OrcaSlicer Others tab; PrusaSlicer right-click → Wipe options). Add walls if dark infill shows through light walls.
  • Lower the flush multiplier carefully (e.g. 1.0 → 0.8–0.9) and check for colour bleed; dark-to-light needs the most.
  • Don't mix unrelated models with different colour layouts on one plate — in the UNBC test this roughly doubled both changes and waste.
  • For lots of colour work, a tool changer or dual nozzle wastes far less (vendors claim up to 80–85 % less, measured on their own tests).

Colour-change strategies

No extra hardware. In the slicer's layer preview, add a colour change (M600) or pause (M601) at the layer where the colour should switch; the printer parks, you swap filament, it purges and continues. Perfect for two-tone signs, lettering on a base, or embedding magnets/nuts.

  • Marlin needs ADVANCED_PAUSE_FEATURE (and a display) for M600.
  • Klipper has no built-in M600 — define one as a macro on PAUSE/RESUME.
  • Doesn't work with sequential (one-at-a-time) printing in PrusaSlicer.

Assign colours by height range or per object. Each layer has at most a few changes, so waste is modest. Good for stacked-colour logos, keychains, and lithophane-style relief.

Paint faces in the slicer (colour painting / MMU painting) or import a 3MF with per-part colours. Most flexible, but every layer that contains several colours costs one purge per extra colour — expensive on tall models.

Design so each colour occupies a contiguous band of layers (e.g. text raised on top, a coloured base on the bottom). Merge visually similar colours into one filament. Limit the number of colours on any single layer.

Colour order and flushing

Changing dark → light needs the most purge (black or red into white is the worst case); light → dark needs very little. Slicers handle this through the flushing volume matrix — leave it at the default for dark → light, and trim the light → dark entries if you need to save filament. Glitter, silk and soluble filaments may need more.

Support-interface materials

A second material that doesn't bond well to the model can be used just for the support interface layers (the layers touching the part). The supports snap off cleanly and leave a smoother surface, without the cost of printing the whole support in a special material.

Model material Interface / support material Removal Notes
PLA PETG (interface only) Break away Classic pairing — PLA and PETG barely bond. Use 0 mm top Z distance and dense interface; purge generously when switching back to the model.
PETG PLA (interface only) Break away The same trick reversed.
PLA, PETG Dedicated break-away "support for PLA/PETG" filaments (e.g. Bambu Support for PLA/PETG) Break away Formulated for low adhesion; interface only, not for the support body or raft.
PLA PVA Dissolves in water Very hygroscopic — dry before use and print from a dry box. Support for PETG varies by brand (Bambu lists PLA and PETG; BCN3D says PVA doesn't suit PETG).
PLA, PETG, ABS, nylon, others BVOH Dissolves in water Wider compatibility and roughly 2× faster dissolving than PVA (vendor tests); pricier, also hygroscopic.
ABS HIPS Dissolves in d-limonene, or break away Needs ABS-like temperatures and an enclosure.
ABS Brand "support for ABS" filaments Limonene-dissolvable (Bambu) Check the TDS for the solvent and nozzle needed.
Nylon, PET-CF Brand "support for PA/PET" filaments Break away High temperature (≈280–300 °C for Bambu's) and a hardened nozzle; must be dried.

Material properties and drying temperatures are in Filaments → Support materials and Material Selection; slicer support settings are in Print Settings → Supports.

Interface-only means interface-only

Break-away interface materials and PLA-on-PETG combinations are meant only for the 2–3 interface layers. Printing the whole support (or a raft) in them wastes material, adds changes and can leave residue. If the interface layers slide off angled surfaces, reduce interface spacing and check that support layers stay synchronised with the model layers.

Before you print a big multi-material job

Print a small support test with your exact pair of filaments first — results vary with brand, moisture and Z gap. Design changes that remove the need for supports (chamfers, splitting, reorienting) beat any interface material — see Design for Printing. For problems such as interface layers not sticking or blobs on the prime tower, see Troubleshooting.

Sources & further reading