What is ASA filament? The UV-stable outdoor alternative to ABS

What makes ASA different

ASA was developed as an outdoor-grade replacement for ABS. ABS holds up well to heat and impact but turns yellow and grows brittle under months of direct sun. ASA keeps the same toughness and print behavior while staying stable in UV, which is why it shows up in garden fixtures, electrical enclosures, car exterior parts, and signage.

The catch is that ASA inherits the hard parts of ABS too. It warps without an enclosure, needs a hot bed, and gives off styrene fumes as it prints. If your printer can already run ABS, it can run ASA with the same profile.

ASA print settings, in short

Treat ASA like ABS that happens to survive the sun. Prusament’s ASA targets a 260 C nozzle, within a 10-degree window, and a 110 C bed, run inside an enclosure that holds the chamber warm. Keep part cooling low (Prusament suggests around 30%), and add a brim on parts with a wide base. Dry the filament first, because wet ASA strings and pops like wet ABS.

ASA vs ABS and PETG

The choice between ASA and ABS comes down to sunlight. Pick ASA for anything that lives outside; pick ABS indoors, where its lower cost and wider color range matter more. For a part that needs neither UV resistance nor high heat, ABS and PETG both print easier. The dedicated best filament for outdoor use page walks through the full outdoor comparison.

For where ASA fits among the six common families, read the 3D printer filament overview.