Filament guideWhen PLA and PETG can't take the heat, the next step is usually ABS or ASA. They're close cousins, and on paper they look almost identical. The real difference is sunlight. Here's how Bambu Lab's ABS and ASA compare, and which one we'd pick for your part.
Quick answer
The short answer
ABS (acrylonitrile butadiene styrene) is the plastic LEGO bricks are made of. It's tough, heat resistant and easy to sand. ASA (acrylonitrile styrene acrylate) swaps one ingredient for an acrylic one that resists UV and weather.
Bambu's own advice is simple: ASA for outdoors, ABS for indoors. ASA also handles a bit more heat.
01
What they have in common
Both print hot, at 240–270°C (464–518°F) in Bambu's settings, on a bed of 80–100°C. Both have a density of 1.05 g/cm³, so parts are lighter than the same part in PLA or PETG.
Both also shrink as they cool, which can make corners lift off the bed. That's why Bambu says both require an enclosed printer. They give off a noticeable smell while printing, so ventilation matters too.
02
ABS vs ASA, by the numbers
Bambu publishes a direct comparison of the two.
| Bambu's test | ABS | ASA |
|---|---|---|
| Heat deflection (0.45 MPa) | 87°C | 100°C |
| Impact strength (XY) | 39.3 kJ/m² | 41.0 kJ/m² |
| Bending strength (XY) | 62 MPa | 65 MPa |
| Bending modulus (stiffness) | 1,880 MPa | 1,920 MPa |
| Layer adhesion (Z impact) | 7.4 kJ/m² | 4.9 kJ/m² |
| Water absorption | 0.65% | 0.45% |
ASA edges ahead on heat, 100°C (212°F) versus 87°C (189°F), and absorbs less water. ABS has stronger bonds between layers. Both are far more heat resistant than PETG, which Bambu rates at 69°C.
03
Smell, moisture and finish
Bambu describes ABS as having a pungent smell while printing, and ASA a lighter one. We print both in an enclosed machine, so the finished part has no lingering odor issue for you.
Both pick up moisture from the air, and Bambu recommends drying them before printing. We handle that in the studio.
04
When to choose ASA
- Outdoor signage, house numbers and mailbox parts
- Car exterior trim, mirror housings and mounts
- Garden fixtures, planters and enclosures for outdoor electronics
- Anything that will sit in a sunny window for years
Bambu says ASA resists fading, yellowing and breakdown in sunlight, while keeping ABS's toughness.
05
When to choose ABS
- Indoor functional parts near moderate heat: appliance parts, car interiors
- Housings and enclosures for electronics
- Parts that will be sanded, primed and painted
- Pieces where strong layer bonds matter more than UV life
06
Limits and design tips
- Big, solid parts warp more. Bambu recommends avoiding very large, high-infill models. Splitting a large piece into parts often works better.
- Round the corners. Sharp corners at the base lift first. A small chamfer or fillet helps.
- Not for food. Bambu lists no food-contact certification for either.
- Need more stiffness? ABS-GF and ASA-CF add fiber for rigid parts. ASA Aero is a lightweight foaming version.
07
ABS and ASA at IMPRESO
We print ABS and ASA in-house at our Ridgewood, Queens studio, on an enclosed printer. Tell us where the part will live and how hot or sunny it gets, and we'll recommend the right one. Every job is quoted individually.
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