Soluble filaments are the solution for printing complex geometries, undercuts, and internal cavities where traditional supports would be impossible to remove without damaging the part. Printed with a second print head (dual extruder) or on material changing systems, they create support structures that then dissolve, leaving clean surfaces even in the most difficult areas.
PVA (polyvinyl alcohol) is water-soluble: immerse the finished part and the support dissolves by itself, without mechanical intervention. It is ideal in combination with PLA and materials printed at low temperatures. It must be kept strictly dry, as it absorbs moisture very quickly. HIPS, on the other hand, dissolves in limonene and is the natural companion for ABS: in addition to serving as a support, it can be used as a structural material on its own. BVOH is an alternative to PVA with faster dissolution and better interlayer adhesion, valued in technical applications.
Choosing the right soluble filament depends on the model's material: PVA and BVOH for PLA and PETG, HIPS for ABS and ASA. In all cases, dry storage is crucial: a damp soluble filament loses adhesion and causes stringing. At Strato3D, we select spools from reliable brands, with consistent diameter to ensure smooth extrusion even on the second print head, which is often more delicate to manage. If you don't know where to start, evaluate the model + support combination based on your 3D printer.