ABS is the original engineering plastic of 3D printing — tough, heat-resistant, and the same material as Lego. ASA is its UV-stable sibling, designed for outdoor use. Both warp badly without an enclosure, both off-gas styrene that you shouldn't breathe, and both reward proper temperature management with parts that hold up in cars, in sun, and under load.
Nozzle 240–260 °C, bed 100 °C, fan 0–25%, enclosure mandatory above ~80 mm tall parts. Vent the enclosure to outside — ABS/ASA fumes are unpleasant and potentially irritating. Use glue stick or ABS slurry on the bed. ASA for outdoor parts, ABS for indoor mechanical or acetone smoothing.
Both are styrene-based copolymers from the same chemical family:
For 3D printing purposes they behave nearly identically — same settings, same warping, same fume profile. Pick ASA for anything outdoors; ABS for indoor parts, acetone smoothing, or where cost matters (ABS is slightly cheaper).
Without an enclosed, warm chamber, ABS and ASA warp on anything larger than a small calibration cube. The enclosure does two things:
Both are respiratory irritants. Print enclosed and vented to outdoors, in a garage, or under a fume hood. A HEPA-only filter doesn't remove gaseous VOCs — you need activated carbon or actual outdoor ventilation. See the 3D printing safety guide .
Three options that work:
Plus: a wide brim (8–10 mm), mouse-ears at the corners, and bed temp at the top of the recommended range.
See the dedicated warping guide , but for ABS/ASA specifically:
One of ABS's unique party tricks: acetone vapor dissolves the surface layer, smoothing layer lines into a glossy finish.
Do this outdoors or in a fume hood. No ignition sources. Don't seal in a metal container that could rust into the seal — the resulting pressure-pop is not fun.
Avoid for: parts you'll print without an enclosure, indoor spaces without ventilation, fine miniatures (use PLA), anything bigger than your enclosure's stable warm volume.