Water-Soluble Filament: PVA, BVOH and Support Material for 3D Printing
Water-soluble filament is not a material for the model itself. It is printed as a temporary support structure and dissolved in water after printing, so supports do not have to be broken out of narrow cavities.
The two main materials are PVA and BVOH. They work on the same principle but differ in printability, material compatibility and price. This guide covers both, modified PVA grades, use in automatic material systems, drying, and what to check before buying.
What is water-soluble support filament?
On a dual-extrusion printer or a multi-material system, the model is printed in one material and the support structure wholly or partly in a water-soluble filament. After printing, the part is placed in water and the support gradually dissolves.
Unlike breakaway supports, contact surfaces do not necessarily have to be removed mechanically. That makes internal channels, steep overhangs and geometry with hard-to-reach cavities printable.
Not every soluble support dissolves in water: HIPS, for example, is dissolved with d-limonene and belongs to a different support strategy.
When is soluble support worth it?
Soluble support is most useful for:
- internal supports and channels
- deep or enclosed cavities
- demanding overhangs
- print-in-place mechanisms printed in one piece
- delicate surfaces and demanding overhang undersides
- dual-extrusion and multi-material printing with a soluble interface
For simple, accessible supports, regular breakaway support is usually simpler and more economical.
PVA: the widespread classic
PVA stands for polyvinyl alcohol. It dissolves in water and is used in FDM printing mainly for temporary support structures. It is most commonly paired with PLA because the processing temperatures are relatively close.
| Property | PVA |
|---|---|
| Main use | water-soluble supports |
| Water soluble | yes |
| Moisture sensitivity | very high |
| Common pairing | PLA |
| Typical nozzle range | often around 195–215 °C |
| Typical bed temperature | around 60 °C |
| Storage | sealed and dry |
| Drying | follow manufacturer instructions |
| Main model material | usually no |
The temperatures are typical starting ranges. The profile for the specific filament always takes priority.
PVA+ and modified PVA grades
Besides classic PVA, several manufacturers sell modified grades, often under names such as “PVA+” or with claims of faster dissolving or better adhesion. There is no common definition behind these names: only the manufacturer's data sheet says what a given formulation changes.
For a modified grade, check the same points as for any support material: which model materials the manufacturer has tested it with, which temperatures the profile specifies, how it should be dried, and whether it is approved for your material system. Printer manufacturers also sell their own PVA for their systems. Being matched to one system is an advantage, but not a guarantee for other machines.
BVOH: the more versatile alternative
BVOH stands for butenediol vinyl alcohol copolymer. Like PVA it dissolves in water and is used for temporary supports, while the part itself is printed in PLA, PETG or another compatible material.
The difference is mostly practical. Many BVOH grades bond to a wider range of build materials and are considered less fussy in multi-material printing. In return, BVOH usually costs more.
| Property | BVOH |
|---|---|
| Main use | water-soluble supports |
| Water soluble | yes |
| Moisture sensitivity | very high |
| Material compatibility | broad depending on grade |
| Typical nozzle range | around 190–220 °C for some grades |
| Typical bed temperature | around 60 °C |
| Storage | very dry and sealed |
| Dry-box printing | recommended |
| Cost | usually higher than PVA |
There are no universal print settings for BVOH. The data sheet for the specific product takes priority.
PVA or BVOH? The differences
| Property | PVA | BVOH |
|---|---|---|
| Water soluble | yes | yes |
| Moisture sensitivity | very high | very high |
| Printability | more often sensitive | often easier |
| Adhesion to model materials | depends on grade | often broader |
| Cost | usually lower | usually higher |
| PLA | very suitable | very suitable |
| PETG | depends more on the grade | often more suitable |
The table describes tendencies, not a guarantee for every brand. Exact compatibility depends on the product.
BVOH is often more convenient and versatile. For a PLA model, though, PVA can be entirely sufficient and usually costs less.
Compatibility with PLA and PETG
PLA: PLA pairs very well with both PVA and BVOH because the printing temperatures are relatively close. The bond between model and support still needs testing: a soluble material does not help if the interface layer lets go of the part during printing.
PETG: PVA is not automatically ideal for PETG; adhesion can be insufficient depending on the grade. Many BVOH grades bond well to PETG and are often the more robust option here.
In both cases, residue of the other material in the nozzle can weaken layer bonding, so the purge amount at each material change is part of the test.
Read more: PLA guide, PETG guide.
Full support or interface only?
On multi-material systems, the whole support structure does not have to be soluble.
Full soluble support: the entire support is PVA or BVOH. Advantage: even complex internal supports dissolve completely. Disadvantage: high material use and many material changes.
Soluble interface: only the contact layers between regular support and the model are soluble. Advantage: much lower consumption. Disadvantage: regular support trapped inside the part remains a problem.
AMS, MMU and other material systems
Whether a water-soluble filament works in an automatic material system depends on the exact filament and the exact system. Not every soluble or damp filament suits every system. The approvals of the printer and filament manufacturers are what count.
Pay particular attention to:
- Moisture: an open material system is not dry storage. For long prints, a dry box or a dry, closed system is worthwhile.
- Purge amount: too little purging can leave model material in the support or support residue in the model layers, so very low purge values are not a good default.
- Filament path: guides and feeding must cope with the material. Damp support filament can make feeding harder.
- Interface strategy: a soluble interface instead of full soluble support reduces material changes and consumption.
Keeping it dry and drying it
PVA and BVOH are strongly hygroscopic. Damp filament can:
- extrude unevenly
- form bubbles
- increase stringing
- degrade surface quality
- reduce adhesion
- raise the risk of clogs
Store the filament sealed with desiccant straight after printing, do not leave it exposed longer than necessary, and check moisture first when print problems appear.
There is no universal drying temperature. Instead:
- Check the manufacturer's instructions.
- Dry only in a suitable filament dryer or another controllable device.
- Avoid excessive temperatures, which can damage the spool or the material.
- For long multi-material prints, print from a dry box where possible.
Read more: drying filament, storing filament.
Dissolving the support
Place the finished model in water. How long dissolving takes depends on:
- support volume and support wall thickness
- water movement
- water temperature
- the filament product
- how accessible the support is
It is more efficient to carefully remove large, accessible support sections mechanically first and only dissolve the hard-to-reach remainder.
Warm water and agitation can speed things up, as long as the manufacturer allows it and the model material can take the temperature. With heat-sensitive model materials such as PLA, do not simply use the hottest water available.
There is no universal disposal instruction. Follow the filament manufacturer's guidance and local rules.
What to check before buying
- Model material: does the manufacturer explicitly list your material, such as PLA or PETG, as a tested pairing?
- Profile: is there a print profile for your printer, or at least clear temperature data?
- Material system: is the filament approved for your AMS, MMU or other system?
- Packaging: is it vacuum-sealed with desiccant, and can it be resealed?
- Spool size: smaller spools often make sense, because opened material absorbs moisture before it is used up.
- Drying data: does the manufacturer give a specific drying recommendation your dryer can meet?
At the top of this page you will find a selection of water-soluble filaments on Amazon. Check the details of the specific product before buying.
Frequently asked questions
Is PVA filament completely water soluble?
PVA is used as a water-soluble support material. Dissolving time and residue depend on the specific filament and the geometry.
What is the difference between BVOH and PVA?
Both are water-soluble support materials. BVOH is often easier to print and compatible with a wider range of build materials, while PVA is often cheaper.
Is BVOH always better than PVA?
No. It is often more convenient, but PVA may be entirely sufficient for PLA and can cost less.
Can PVA be printed with PLA?
Yes. PLA and PVA are one of the most common soluble-support combinations.
Which soluble support suits PETG?
It depends on the grade. BVOH is often the more reliable option for PETG. Check the exact pairing with the manufacturer.
Can water-soluble filament be used in an AMS or MMU?
Compatibility depends on the exact filament and material system. Not every soluble or damp filament suits every automatic system. Check manufacturer approval.
Why does PVA suddenly print badly?
Moisture is a common cause. PVA and BVOH absorb water from the air and should be kept very dry.
Do I need soluble support for every supported print?
No. Use soluble support when the geometry justifies the additional material, complexity and cost.
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