What is the difference between ABS and ASA filament?

ASA (Acrylonitrile Styrene Acrylate) is ABS with the butadiene rubber component replaced by an acrylate rubber. This change adds UV stabilization: ASA does not yellow, crack, or become brittle in sunlight. Print settings are nearly identical — same temperature (235–255°C nozzle, 100–110°C bed), same enclosure requirement, same zero fan rule. The only practical reason to choose ABS over ASA is acetone smoothing — ASA does not respond to acetone the same way ABS does.

Is ASA harder to print than ABS?

ASA and ABS have essentially the same print settings and the same print difficulty. Both require an enclosure to prevent warping, 100–110°C bed temperature, 0% fan, and 235–255°C nozzle temperature. If you can print ABS successfully, you can print ASA with the same settings. ASA warps slightly less than ABS in some formulations.

Can ASA be smoothed with acetone?

No. ASA does not dissolve in acetone the way ABS does. The acrylate component in ASA resists acetone. If acetone smoothing or welding is required, use ABS. For outdoor parts where smoothing is also desired, consider post-processing ABS with acetone and then coating with UV-protective paint or clearcoat.

ABS vs ASA

ABS and ASA are so similar that many 3D printing guides treat them as interchangeable. They have nearly identical print settings, the same enclosure requirement, and the same general print difficulty. The difference is what happens to the printed part over time: ASA survives sunlight indefinitely; ABS does not.

At a glance

ABS

Nozzle temp230–255°C

Bed temp100–110°C

Fan speed0–10%

EnclosureRequired

UV resistancePoor

Heat deflection~100°C

Acetone smoothingYes

Color stability outdoorsYellows within months

Cost / kg$18–28

ASA

Nozzle temp235–255°C

Bed temp100–110°C

Fan speed0–10%

EnclosureRequired

UV resistanceExcellent

Heat deflection~98°C

Acetone smoothingNo

Color stability outdoorsStable for years

Cost / kg$22–32

Print settings: identical in practice

You can use your ABS slicer profile for ASA without changes. Both materials print at:

Nozzle: 235–250°C (ABS slightly lower minimum; ASA slightly higher recommended)
Bed: 100–110°C on PEI, glass, or Garolite
Fan: 0% throughout (some ASA formulations tolerate 5–10% fan after layer 5)
Enclosure: required for both — both warp severely in open air
Retraction: 0.5–2 mm direct drive, 3–5 mm Bowden

If your prints in ABS are successful, switching to ASA requires no setting changes. Run a test print to confirm, then proceed with your production settings.

Why UV resistance matters

ABS contains polybutadiene rubber as an impact modifier. Polybutadiene is highly reactive to UV and oxygen. Months of outdoor exposure breaks these double bonds, causing visible yellowing, surface chalking, brittleness, and eventual cracking. A part printed in ABS placed on a south-facing windowsill or on a vehicle exterior will degrade visibly within 3–6 months.

ASA replaces polybutadiene with an acrylate rubber that does not react to UV. The result is a material that maintains its color and mechanical properties for years of outdoor exposure. Testing at standardized UV aging conditions (ASTM D4329) shows ASA retaining over 90% of its impact strength after 1,000 hours of UV exposure, where ABS loses 50%+ in the same test.

Choosing between ABS and ASA

Choose ABS when: You need acetone vapor smoothing or acetone welding. The part will be used exclusively indoors away from UV. You already have ABS filament and the application does not require outdoor exposure.
Choose ASA when: The part will be used outdoors, near windows, in a vehicle, or in any UV-exposed environment. You want long-term color and mechanical stability. Post-processing with acetone is not required.

In practice, ASA is the better default for any part that might spend time in sunlight. The slight premium (typically $4–8/kg more than ABS) is worth it for the dramatically better outdoor durability.

ASA and ABS settings in the database

ABS settings database →ASA settings database →ABS printing guide →ABS temperature guide →

Browse ABS / ASA settings by printer

All ABS settings → · All ASA settings →