ASA vs ABS: The Outdoor Question, Settled
Updated 2026-06-11 · by Jay
ASA was engineered to fix ABS's one fatal flaw — sunlight. For most uses where people historically said "ABS", the modern answer is ASA.
The one decisive difference
UV stability. ABS outdoors yellows, fades, and turns brittle in months. ASA holds color and toughness for years — it's what automotive exterior trim is made of. If the part sees sun or weather, ASA wins before any other property is discussed.
Everything else is nearly a tie
- Strength/heat: same class — rigid, impact-resistant, ~95-100°C service temperature.
- Printing: both want 240-270°C nozzles, 90-110°C beds, an enclosure, and ventilation (both emit styrene). If your printer handles one, it handles the other with the same profile ± 5°C.
- Price: ASA runs slightly higher; the gap has narrowed every year.
Where ABS still earns its keep
Acetone vapor smoothing is ABS's party trick — glass-smooth surfaces with no sanding. ASA smooths inconsistently. ABS also sands and machines beautifully, and decades of community knowledge mean any problem you hit has been solved before.
The decision rule
Outdoors or near a window: ASA, no debate. Indoors with post-processing plans: ABS. Indoors without: either — or honestly, reconsider PETG, which covers most "I need ABS" jobs without the enclosure and fumes.
