Polyvinyl alcohol (PVA) is soluble in water, and that’s exactly what commercial applications take advantage of. Popular uses include packaging for dishwasher detergent “pods” or bags full of fishing bait. (Throw the bag in water and watch it dissolve, releasing the bait.)
The same principal applies in 3D printing, making PVA a great support material when paired with another 3D printer filament in a dual extrusion 3D printer. The advantage of using PVA over HIPS is that it can be printed with more than just ABS.
The trade-off is a 3D printer filament that is slightly more difficult to handle. One must also be careful when storing it, as even the moisture in the atmosphere can damage the filament prior to printing. Dry boxes and silica pouches are a must if you plan to keep a spool of PVA usable in the long run.
When Should I Use PVA 3D Printer Filament?
PVA filament is a great choice as a support material on complex prints with overhangs.