ABS vs ASA: print settings, enclosure and warping fixes
ABS prints at 235–255 °C and ASA at 240–260 °C, both on a 95–110 °C bed with 0–25% part cooling, inside an enclosure, in a ventilated room. Pick ASA for outdoor parts because it resists UV; pick ABS for indoor parts where cost matters. Both hold their shape to roughly 90–100 °C, far beyond PLA or PETG.
- Nozzle: ABS 235–255 °C, ASA 240–260 °C. Fast printers often run 10–20 °C hotter.
- Bed 95–110 °C on PEI with a thin layer of glue stick.
- Part fan 0–25%, off for the first layers; a little more for bridges.
- Enclosure closed, no drafts, and the room ventilated or the enclosure vented outside.
- Brim on large or sharp-cornered parts.
ABS and ASA print settings table
Starting values for enclosed printers such as the Bambu Lab P1S, P2S, X1 and H2 series, Prusa CORE One, Creality K-series and Qidi machines. Your spool's label wins if it disagrees.
| Setting | ABS | ASA |
|---|---|---|
| Nozzle temperature | 235–255 °C | 240–260 °C |
| High-speed printing | Up to about 260–280 °C | Up to about 260–280 °C |
| Bed temperature | 95–110 °C | 100–110 °C |
| Chamber | Enclosed; 40–60 °C passive is fine | Same |
| Part cooling fan | 0–25%; 0% for the first layers | 0–25%; up to 30–50% briefly for bridges |
| Bed surface | Smooth or textured PEI with glue stick | Same |
| Brim | 3–10 mm on large or sharp-cornered parts | Same |
| Retraction | 0.5–1.5 mm direct drive; 3–5 mm Bowden | Same |
| Shrinkage | About 0.5–1% | About 0.5–1% |
| Drying | 65–80 °C, 4–8 h | 65–80 °C, 4–8 h |
| Glass transition (Tg) | About 100–105 °C | About 100 °C |
| HDT (0.45 MPa) | About 87–100 °C | About 93–103 °C |
| Fumes | Styrene and ultrafine particles: ventilate | Same, with slightly less odor |
Why the high-speed row? The faster plastic moves through the hotend, the less time it has to heat up, so every filament needs a hotter nozzle at high flow. Bambu Lab's own ABS and ASA data sheets span 240–280 °C for that reason.
ABS vs ASA: what's the difference?
Both are styrene-based plastics from the same family. ABS (acrylonitrile butadiene styrene) is the LEGO-brick plastic. ASA (acrylonitrile styrene acrylate) swaps the butadiene rubber for an acrylic rubber, and that one change makes it weather-resistant.
| ABS | ASA | |
|---|---|---|
| UV and weather resistance | Poor: yellows and turns brittle outdoors | Excellent: the outdoor choice |
| Heat resistance | Very good | Very good |
| Warping | High | High, but a little less than ABS |
| Odor while printing | Strong | Noticeable, a little milder |
| Acetone smoothing and gluing | Yes | Yes |
| Price and color range | Usually cheaper, more colors | Slightly more expensive |
Choose ASA for anything that lives outside: car exterior trim, garden fittings, mailbox parts, outdoor RC.
Choose ABS for indoor heat-resistant parts, car interior clips and brackets, and budget functional prints.
Enclosure and ventilation
ABS and ASA shrink as they cool. Without a warm, still chamber, the bottom layers cool faster than the top, the part pulls itself off the bed, and tall parts crack between layers. An enclosure fixes this by keeping the air around the part warm (40–60 °C) and blocking drafts, even a ceiling fan across the room.
Options, from best to cheapest: a factory-enclosed printer, a fabric or acrylic enclosure for an open-frame machine such as an Ender 3, or a DIY box. Prusa's tip for open printers is a tall skirt ("draft shield") around the part, which helps small prints but won't save big ones.
Ventilate. ABS and ASA release styrene and ultrafine particles while printing. NIOSH recommends local exhaust or a ventilated enclosure, and keeping people from working right next to the printer. A HEPA filter alone catches particles but not gases; you also need activated carbon or venting to outdoors. Ventilate the room, not the print: a draft across the part brings warping back. See the 3D printing safety guide.
Check your printer's own parts. On printers with PLA or PETG fan shrouds and brackets, a hot chamber can soften them. Prusa recommends reprinting those parts in a heat-resistant material if they start to deform.
How to stop ABS warping
Warping is ABS's signature move. This checklist fixes nearly every case; the full version is in warping and curling.
- Close the enclosure and preheat it for 10–15 minutes with the bed on.
- Bed at 100–110 °C with a thin coat of glue stick on clean PEI.
- Add a 5–10 mm brim on large parts and anything with sharp corners.
- Turn the part fan down to 0–25%. Never 100%.
- Round off bottom corners in CAD (a 1–3 mm fillet) so there's no sharp point to lift.
- Lay the largest flat face on the bed and keep it away from the enclosure walls.
- Slow the first layer to 15–25 mm/s if corners still lift.
A tall ABS part cracks between layers halfway up. What's the most likely cause?
As a tall part rises above the heated bed, it relies on warm chamber air. Drafts or a high fan speed chill the fresh layers, they shrink, and the part splits along a layer line. Close the enclosure and cut the fan.
Shrinkage and dimensional accuracy
ABS and ASA shrink roughly 0.5–1% as they cool, so a 100 mm part can come out 99–99.5 mm. Prusa notes ABS parts can shrink 1–2% in some cases, so measure a test print of your own part before scaling. For holes and press fits, scale the model or the slicer's XY compensation rather than guessing.
Free PrintPal toolMaterial Shrinkage CalculatorEnter your target size and shrinkage to get the exact scale factor for ABS or ASAOpen toolABS and ASA heat resistance
ABS has a glass transition near 100–105 °C (Polymaker PolyLite ABS: 101 °C) and ASA near 100 °C (Polymaker ASA: 98 °C). Data-sheet HDT values at 0.45 MPa are 87 °C for Bambu ABS, 100 °C for PolyLite ABS, 93 °C for Prusament ASA and 100 °C for Bambu ASA.
That comfortably covers car interiors, which can pass 70 °C in summer sun, plus enclosures near motors and electronics. For parts that must carry load near 100 °C, step up to polycarbonate or a fiber-filled nylon; see the engineering filaments guide.
Acetone smoothing ABS and ASA
Acetone vapor melts the outer skin of ABS and ASA, turning layer lines into a glossy, injection-molded look. It also glues ABS and ASA parts together: a little acetone on both faces and a firm press.
- Work outdoors or in a well-ventilated space, with nitrile gloves and no flames, sparks or heaters nearby.
- Line a glass jar or container with paper towels dampened with acetone, keeping the liquid away from the bottom.
- Stand the part on a small platform (a bottle cap or foil square) so it doesn't touch wet towels.
- Close the lid loosely and check every 5–10 minutes. Small parts can be done in 15–30 minutes.
- Remove and let it cure 24 hours before handling; the surface stays soft until the acetone evaporates.
Acetone is highly flammable. Never heat it to speed things up, never use it near an ignition source, and store it sealed away from the printer.
Drying ABS and ASA
ABS and ASA absorb less water than PETG or nylon, but a spool that sat out for weeks will pop, string and lose gloss. Dry at 65–80 °C for 4–8 hours: Polymaker lists 70 °C for 6–7 hours, Prusa 80 °C for 4 hours for ASA, and Bambu 80 °C for 8 hours. More in the filament drying guide.
Free PrintPal toolFilament Drying GuidePick ABS or ASA and how long it sat out for a drying time and safe temperatureOpen toolABS and ASA troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Corners lifting | Cold chamber, drafts, sharp corners | Close and preheat the enclosure, bed 100–110 °C, brim, fillet corners. |
| Cracks between layers on tall parts | Upper layers cooling too fast | Enclosure closed, fan 0–15%, nozzle up 5 °C. |
| Part won't stick at all | Bed too cool or dirty | Wash the plate, add glue stick, bed to the top of the range. |
| Part comes out undersized | Thermal shrinkage | Measure a test print and scale by the shrinkage factor. |
| Bulging bottom layers | Bed hot and first layer over-squished | Raise the Z-offset slightly; use elephant's foot compensation. |
| Popping, bubbles, dull surface | Wet filament | Dry at 65–80 °C for 4–8 hours. |
| Strong smell in the room | No filtration or venting | Carbon + HEPA filter or vent outdoors; move the printer out of living space. |
| Saggy bridges | Fan too low for that feature | Raise bridge fan to 30–50% only for bridges. |
| Printer's plastic parts deforming | Hot chamber softening PLA/PETG parts | Reprint them in ABS, ASA or PC. |
Frequently asked questions
What is the difference between ABS and ASA?
ASA replaces the butadiene rubber in ABS with an acrylic rubber, so it resists UV and weathering. They print almost the same way; ASA warps and smells a little less, while ABS is usually cheaper.
What temperature should I print ABS at?
Print ABS at 235–255 °C on a 95–110 °C bed with the part fan at 0–25%, inside an enclosure. ASA prefers 240–260 °C on a 100–110 °C bed. Fast printers often run both 10–20 °C hotter.
Does ABS need an enclosure?
For anything bigger than a small part, yes. An enclosure keeps the air around the print warm and draft-free, which prevents warping and layers splitting apart.
Are ABS fumes dangerous?
ABS and ASA release styrene and ultrafine particles while printing. Print in an enclosure with activated carbon and HEPA filtration or vent it outdoors, and keep the printer out of bedrooms and living spaces.
Can you acetone smooth ASA?
Yes. ASA dissolves in acetone like ABS, so vapor smoothing works on both. Do it outdoors or in a well-ventilated area away from flames, and never heat the acetone.
Related articles
Sources & further reading
- Prusa Knowledge Base: ABS material guide and ASA material guide
- Bambu Lab Wiki: ABS / ASA / PC usage guide
- Prusament: Prusament ASA technical data sheet
- Polymaker: PolyLite ABS technical data sheet
- NIOSH: 3D printing with filaments: health and safety questions to ask
Tools for thisAll tools
Watch it doneVideo library
Thanks! We read every note and use them to decide what to update next.