Material Comparison

PLA vs ASA

The easy indoor filament vs the UV-stable outdoor one. If your print lives inside, use PLA. If it goes outside, use ASA. It really is that simple.

Last updated: March 2026

For a full side-by-side comparison of PLA, ASA, and 6 other materials, see our master comparison table:

Materials Comparison Table

When to use

PLA

PLA is the path of least resistance. It prints at 190-220 °C[1], does not need an enclosure, barely warps, and comes in more colors and specialty finishes than any other material. If your print stays indoors and does not need to survive heat above 55-60 °C, PLA will give you the best surface quality with the least effort. It is also the most affordable filament you can buy.

Ideal for: decorative prints, prototypes, miniatures, cosplay props, office organizers, and anything that stays indoors at room temperature.

Community tip: PLA is biodegradable in industrial composting facilities, not in your garden. Do not leave PLA prints outdoors expecting them to decompose cleanly - they will just get brittle and ugly first.

Browse PLA Deals Best Value PLA Guide

When to use

ASA

ASA was designed for outdoor applications. It is essentially ABS with UV stabilizers baked in[2]. It handles direct sunlight without yellowing or becoming brittle, has a glass transition around 100 °C (so it will not soften in a hot car), and offers good impact resistance. The catch: ASA prints at 240-260 °C, requires an enclosure to prevent warping, and emits styrene fumes that need proper ventilation.

Ideal for: garden fixtures, outdoor enclosures, car accessories, mailbox parts, weather stations, birdhouses, and any functional part exposed to sun and weather.

Community tip: ASA is the go-to material for Voron printer builds and other DIY 3D printer parts. It is popular in the self-sourcing community because it handles the heat inside an enclosed printer without softening.

Browse ASA Deals Best Value ASA Guide

The community verdict

Indoor = PLA. Outdoor = ASA. That is the decision tree. There is no reason to wrestle with ASA's enclosure requirements, warping, and fumes for a print that will sit on your desk. And there is no reason to use PLA for a part that will see UV exposure - it will degrade within months.

If you are on the fence, ask one question: will this part ever be in direct sunlight or above 55 °C? If yes, use ASA. If no, use PLA and enjoy the easier print. PETG sits in the middle if you need moderate outdoor resistance without the enclosure requirement - see our PLA vs PETG comparison or ABS vs ASA comparison for more.

Frequently Asked Questions

How long does PLA last outdoors?

It depends on climate and sun exposure. In a shaded, temperate location PLA can last 6-12 months before becoming noticeably brittle. In direct sunlight or hot climates (35 °C+), PLA can start warping within weeks. The glass transition temperature is only around 60 °C[1], so a car dashboard or south-facing windowsill in summer will destroy it. For anything meant to stay outside permanently, use ASA or PETG.

Does ASA smell as bad as ABS when printing?

ASA emits similar fumes to ABS (both are styrene-based), though some users report ASA is slightly less pungent. Regardless, you should always use an enclosure with ventilation or a carbon filter when printing ASA. Do not print it in an enclosed living space without proper fume extraction. See our ventilation guide for setup advice.

Can I print ASA without an enclosure?

Technically yes for very small parts, but you should not. ASA warps aggressively without an enclosure, and even slight drafts can cause layer splitting. An enclosure is effectively mandatory for reliable ASA printing. It also contains the fumes, which is important for health reasons.

Is PETG better than ASA for outdoor use?

PETG is better than PLA outdoors but not as good as ASA. PETG has decent UV resistance and a higher glass transition than PLA (~80 °C vs ~60 °C), but ASA was specifically formulated for UV stability and outdoor weathering. For permanent outdoor installations, ASA is the better choice. For semi-outdoor or shaded applications, PETG can work fine.

Is ASA stronger than PLA?

ASA has better impact resistance and does not shatter like PLA does under sudden force. PLA is actually stiffer (higher tensile modulus), which means it resists bending better but snaps when it fails. ASA deforms before breaking. For functional parts that take repeated stress or impact, ASA is stronger in practical terms. For rigid parts that just need to hold shape indoors, PLA is adequate.

References

Prusa Knowledge Base - PLA. https://help.prusa3d.com/article/pla_2062
Prusa Knowledge Base - ASA. https://help.prusa3d.com/article/asa_2063