How to print PLA with PVA supports on a dual nozzle printer

Load PLA in one nozzle and dried PVA (polyvinyl alcohol) in the other, with PVA on the right nozzle of a Bambu Lab H2D or X2D. In Bambu Studio, set both support filament fields to PVA and the top and bottom Z distance to 0 mm. Print PVA at 220 to 250 °C, then dissolve it in water no warmer than 50 °C.

How do you print PLA with PVA supports on a dual nozzle printer?

Give PVA its own nozzle, then set Support/raft base and Support/raft interface to PVA under Process → Support → Filament for Supports in Bambu Studio. Use normal supports with top and bottom Z distance at 0 mm. Dry the PVA first and keep it sealed while printing, then soak the finished part in water.

Bambu Lab lists PVA for PLA and PLA-CF/GF only and says PVA “is not compatible as support filament for PETG filament printing”. For other model materials, see the support material table.

Why use a second nozzle for support material?

On one nozzle, every switch between model and support filament means flushing the old filament out of the hotend. Bambu Lab’s dual-nozzle slicing guide says printing different filaments on different nozzles replaces that flush with a nozzle switch. Bambu Lab sells the H2D on the same idea: “one nozzle can be reserved for dedicated support material”.

A switch still costs time. In Bambu Lab’s H2D tests with PLA and PETG, each nozzle change took about 5 seconds, plus a stop at the prime tower to rebuild nozzle pressure. Supports printed in the second material on every layer gave the longest print. Dual-nozzle purge waste covers what the prime tower still uses.

How to print PLA with PVA supports on a Bambu Lab H2D or X2D

1. Dry the PVA. Dry it in a forced-air oven at 80 °C for 8 to 12 hours, or use a method from the drying table. It is dry enough when it bends stiffer than a strand of PLA Basic.
2. Load PVA on the right nozzle. On the X2D, Bambu Lab recommends the left hotend for the model and the right auxiliary hotend for support filament. On the H2D, Bambu Lab’s slicing guide prefers the right nozzle for any filament both nozzles can print. Put the PVA spool in the AMS (Automatic Material System) unit or dry box that feeds that nozzle (assigning filament to the left or right nozzle).
3. Enable normal supports. In Process → Support, tick Enable support and pick normal(auto). Bambu Lab’s PVA guide advises against tree supports with PVA: they grow tall and thin and tend to collapse.
4. Set the support filament. Under Filament for Supports, set Support/raft base and Support/raft interface to PVA. To print a PLA support body with PVA only where it touches the part, set the base to PLA instead.
5. Close the gap. Under Advanced, set Top Z distance and Bottom Z distance to 0 mm. Bambu Lab’s presets also add 2 raft layers.
6. Check temperatures. Bambu Lab’s H2D presets print PVA at 240 °C and PLA Basic at 220 °C. Keep chamber heating off. The data sheet lists a 25 to 45 °C chamber for PVA.
7. Slice and check the grouping. After slicing, open Filament Grouping and confirm PVA is on the nozzle whose AMS holds it. A filament assigned to one nozzle cannot be swapped to the other in the send dialog.
8. Print with the PVA sealed. Keep it below 20% relative humidity (RH) for the whole print. Freshly dried PVA in a 55% RH room goes damp within 1 to 3 hours.
9. Dissolve the supports. Soak the part in water no warmer than 50 °C. Pull softened PVA off by hand instead of waiting for all of it to dissolve.

Using PrusaSlicer or another dual-extruder printer

The settings have the same names elsewhere. On a Prusa XL, pick the “Soluble Full” print preset and set the support and interface extruders under Print Settings → Multiple Extruders. Prusa notes that with a wipe tower, a separate support extruder only works with Organic supports.

Bambu Lab H2D PVA support settings

These are the values in Bambu Lab’s two H2D preset files (0.4 mm nozzle, 0.20 mm Standard profile), downloadable from its PVA guide. Import your model into the preset and these settings come with it.

Setting	Full PVA preset	PVA interface preset	Where in Bambu Studio
Support type	normal(auto)	normal(auto)	Process → Support
Threshold angle	40°	40°	Process → Support
Raft layers	2	2	Process → Support → Raft
Support/raft base	PVA	PLA Basic	Filament for Supports
Support/raft interface	PVA	PVA	Filament for Supports
Top / bottom Z distance	0 mm / 0 mm	0 mm / 0 mm	Support → Advanced
Top / bottom interface layers	2 / 2	2 / 2	Support → Advanced
Interface spacing	0 mm	0 mm	Support → Advanced
Base pattern, spacing	Rectilinear, 1 mm	Rectilinear, 1 mm	Support → Advanced
Support / interface speed	120 / 50 mm/s	120 / 50 mm/s	Process → Speed
Nozzle: PLA Basic / PVA	220 °C / 240 °C	220 °C / 240 °C	Filament presets
Plate	Textured PEI, 55 °C	Textured PEI, 55 °C	Plate type
Prime tower	On, 60 mm wide	On, 60 mm wide	Process → Others

Bambu Lab’s filament guide recommends opening the door or removing the top glass when the bed is above 45 °C with PLA or PVA. Otherwise chamber heat can soften the filament in the extruder.

Bambu Lab X2D PVA support

The X2D’s right nozzle is the auxiliary nozzle. Its extruder sits on the back of the top panel and feeds through a long PTFE tube. Bambu Lab’s X2D extruder article lists PVA among the recommended filaments and puts support filament on the right hotend. Using the auxiliary hotend costs 4 mm of print height, and it runs at up to 200 mm/s with acceleration up to 1000 mm/s².

Bambu Studio’s X2D Quality Mode does the grouping for you: once you set a support filament by hand, the right nozzle prints only support and the left only the model. Bambu Lab says the auxiliary nozzle prints at slightly lower quality than the main one, which matters little for support. H2D vs X2D compares the two machines.

Full PVA supports or a PVA interface only?

Bambu Lab’s PVA guide recommends PVA for both the support base and the interface. Its store page says PVA can print the interface alone “to minimize material waste and printing time”, and its guide includes a PLA-base, PVA-interface preset for the H2D.

	Full PVA	PVA interface, PLA base
PVA used	Whole support	Only the layers touching the part
Nozzle switches	Every layer with support	Only on interface layers
Removal	Everything dissolves	PVA dissolves, then the PLA body lifts out
Suits	Enclosed cavities, internal channels	Supports you can reach once the interface is gone

Bambu Lab measured the time difference with PETG parts. Moving the second material from the whole support to the interface only cut 1 hour 20 minutes from a 5 hour 3 minute print and roughly halved prime tower waste. Bambu Lab has not published a PVA figure.

How do you dry and store PVA?

Method	Temperature	Time	Source
Forced-air oven	80 °C	8 to 12 h	PVA data sheet
Forced-air oven	85 °C	8 to 12 h	PVA printing guide
Printer heatbed (X1, X1C, P1S, H2D), covered by the spool’s carton	100 °C	12 h, turned every 6 h	PVA printing guide
AMS HT	85 °C	18 h	Filament guide
AMS 2 Pro	Not recommended for PVA		Filament guide

Bambu Lab’s general filament table also gives 55 °C for 8 hours in an oven. The PVA-specific guide and data sheet give the higher figures.

• Move it straight into dry storage. Bambu Lab says to put PVA in a dry box or the AMS right after drying, without waiting for it to cool.
• Use calcium chloride. Bambu Lab says silica gel cannot keep PVA dry for long. At 20% RH, dried PVA stays usable for about 1 to 3 days.
• AMS HT as a dry box. During the print, run its drying mode at about 80 °C with “Rotate Spool When Drying” off. Automatic load and unload do not work while it dries.
• Damp PVA turns soft and sticky. In that state it no longer feeds through the AMS and must be dried again.

How do you dissolve PVA supports?

Soak the part in water. Bambu Lab says it takes from a few hours to a dozen hours. Warm water and stirring speed it up, but keep the water at or below 50 °C with PLA parts so they do not deform. Pull partly dissolved PVA off by hand to save time.

Printed parts have voids, so water can seep inside during the soak. Bambu Lab’s PVA guide links a separate guide on reducing that leakage.

Which support material works with which filament?

PVA dissolves in water and supports PLA, but Bambu Lab says not PETG. BVOH (butenediol vinyl alcohol) also dissolves in water and works with PLA, ABS and PET. Breakaway Support for PLA/PETG peels off both. ABS takes a limonene-soluble support, PA and PET composites take Support for PA/PET, and PETG can be the breakaway interface under PLA.

Compatibility and nozzle temperatures below are as published by each maker on 2026-10-12, sorted by the lowest nozzle temperature.

Support material	Nozzle temp	Removal	Model filaments (per maker)
Breakaway support for PLA/PETG	190 to 220 °C	Peel off	PLA, PLA-CF/GF, PETG, PETG-CF/GF
BVOH	200 to 220 °C	Dissolves in cold water	ABS, PLA, PET
Breakaway support for PLA	220 to 230 °C	Peel off	PLA, PLA-CF/GF
PVA	220 to 250 °C	Dissolves in water, at or below 50 °C for PLA	PLA, PLA-CF/GF (not PETG)
HIPS (high-impact polystyrene)	225 to 255 °C	Dissolves in limonene	PETG (Prusa: not ABS or ASA, which limonene also attacks)
PLA Basic as interface	230 °C	Peel off	PETG HF, PETG Basic
Limonene-soluble support for ABS	240 to 270 °C	Dissolves in limonene	ABS
PETG HF as interface	265 °C	Peel off	PLA Basic
Breakaway support for PA/PET	280 to 300 °C	Peel off within 2 h of the print ending	PAHT-CF, PA6-CF, PA6-GF, PET-CF

• Interface-only materials. Bambu Lab sells its breakaway support for PLA/PETG and for PA/PET as interface-only filaments. Set them under Support/raft interface and leave the base on the model filament.
• PLA and PETG as each other’s interface. Bambu Lab’s mutual-support guide covers only Bambu PLA Basic, PETG HF and PETG Basic. Under PLA, it sets PETG’s max volumetric speed to 10 mm³/s.
• Mixed materials need a hotter nozzle. A support that prints much hotter than the model needs a nozzle and printer that reach its range. The X2D tops out at 300 °C and the H2D at 350 °C. Pairing a flexible filament with a rigid one is a separate case (TPU and PETG in one print).

What if the PVA support print fails?

• PVA will not load or jams in the AMS. It has absorbed moisture. Dry it again and check it with the bend test.
• Extrusion is weak, bubbly or curls sideways. Feed PVA by hand at 240 to 250 °C first. If extrusion stays abnormal on dry filament, Bambu Lab says to do a cold pull or replace the nozzle.
• Tree supports topple. Switch to normal supports.
• You are on a 0.2 mm nozzle. Bambu Lab lists its PVA as not compatible with the 0.2 mm nozzle. Use 0.4 mm or larger.
• Supports detach or the motor overloads. Forum user mecha reported stable H2D prints after lowering PVA to 220 °C, slowing support speeds to 10 to 30 mm/s and switching from a PLA base to full PVA supports.
• The part softens on the plate. Open the door or remove the top glass, as above. Dual-nozzle ooze covers stringing from the idle nozzle.