Key takeaways
- Heat is the first filter: on Polymaker's data sheets PLA reaches 53–60 °C HDT, PETG 76–78 °C, ABS and ASA 100–106 °C.
- PLA is the strongest of the three in a tensile test and the weakest in a drop test. Stiffness is not toughness.
- None of the three is genuinely UV stable. For sustained sun, the answer is ASA.
- Print difficulty tracks in the opposite direction to performance. Budget an enclosure before you buy ABS.
Most filament comparisons rank materials from worst to best. That is the wrong shape for the decision. These three polymers fail in different ways, and the useful question is which failure your part can afford.
So work backwards from the part. Where does it live, what pushes on it, and how hot does it get? Three questions decide it almost every time.
The short version
| PLA | PETG | ABS / ASA | |
|---|---|---|---|
| HDT 0.45 MPa | 53–60 °C | 76–78 °C | 100–106 °C |
| Tensile strength | 23–52 MPa | 38–51 MPa | 33–44 MPa |
| Elongation at break | 6.3 % | 8.4 % | 6.7–17.9 % |
| Impact, notched Charpy | 3.3–10 kJ/m² | 2.6–11.6 kJ/m² | 10.3–18.0 kJ/m² |
| Water resistance | Poor | Good | Good |
| UV stability | Poor | Fair | Poor (ABS) / Good (ASA) |
| Enclosure needed | No | No | Yes |
| Ventilation needed | No | No | Yes |
Where does the part live?
This filter removes more candidates than any strength number. A part on a desk has no thermal problem. A part in a car in Ho Chi Minh City has nothing but thermal problems: a closed cabin in direct sun reaches 60–70 °C, which is past the point where PLA goes soft and starts to creep under its own mounting load.
- Indoors, room temperature — all three work. Pick on cost and print time, which means PLA.
- Indoors, near heat — a motor housing, a lamp, an enclosure with a power supply in it: PETG at minimum, ABS if it sits above 70 °C.
- Outdoors, shaded — PETG. It ignores rain and does not mind thermal cycling.
- Outdoors, direct sun — ASA. PLA becomes brittle and chalky in months; PETG yellows and loses impact strength; ABS surface-cracks. ASA was designed for exactly this.
What pushes on the part?
Here is where data sheets mislead people. PLA has the highest tensile strength of the three, which is why it wins spec-sheet comparisons. It also has 4 % elongation at break, which means it snaps with no warning. PETG stretches to 18 % before it fails, and ABS absorbs four to five times PLA's impact energy.
Tensile strength tells you when a part breaks. Elongation tells you whether it warns you first.
For a bracket under steady load, PLA is fine and stiffer than the alternatives. For a handle, a clip, a drone arm, or anything that gets dropped, the impact number is the one that decides, and PLA loses badly.
What will printing it cost you?
Print difficulty runs in the opposite direction to performance, and it is a real cost — in failed prints, in hardware, and in the time you spend tuning instead of designing.
Starting settings, ZORVA grades
- PLA Matte
- 205–220 °C nozzle · 55–65 °C bed · no chamber · 100 % fan
- PETG Core
- 235–250 °C nozzle · 75–85 °C bed · optional chamber · 40–60 % fan
- ABS Core
- 245–265 °C nozzle · 95–110 °C bed · 45–55 °C chamber · 0–20 % fan
- ASA Core
- 250–270 °C nozzle · 100–110 °C bed · 50–60 °C chamber · 0–15 % fan
PLA prints on anything. PETG needs dry filament and slower speeds, and it sticks to smooth PEI hard enough to take chips out of the plate — use a textured sheet. ABS and ASA need chamber heat to stop the lower layers contracting and splitting the part, plus extraction, because both release styrene while printing. That is not a preference. Print them in a closed room and you will smell why.
The three mistakes we see most
- Buying ABS without an enclosure. Anything with a footprint over roughly 80 mm will warp or delaminate. The material is not at fault.
- Using PETG like PLA. Same speed, same 100 % fan, wet spool. The result is stringing, weak layer bonds and a part that looks worse than PLA and performs no better.
- Choosing PLA for a car interior part. It will not fail on the bench. It will fail in the third week of afternoon sun, quietly, by sagging.
What about the materials past these three?
If the answer to all three questions is demanding — hot, loaded and outdoors — then the honest answer is that none of these three is right. That is what nylon and composites and polycarbonate are for. They cost more, need a dryer and an enclosure, and they hold 115–185 °C while carrying real load.
Every ZORVA grade publishes the same settings and the same test context on its Material Passport, so you can compare like with like before you buy a spool.
Frequently asked
Is PETG stronger than PLA?
Not in tensile strength — PLA is comparable or slightly higher. PETG is tougher, which is different: it stretches around 18 % before breaking versus PLA's 4 %, and absorbs roughly twice the impact energy. For parts that get dropped or flexed, PETG is the stronger choice; for stiffness under steady load, PLA is.
At what temperature does PLA start to deform?
PLA softens from about 55–60 °C. Under load it can begin to creep below that. A closed car in direct sun exceeds this easily, which is the most common cause of PLA parts sagging in service.
Can I print ABS on an open-frame printer?
Small parts sometimes survive, but anything over roughly 80 mm across will warp or split at the layer lines because the lower layers cool and contract faster than the top. An enclosure holding 45–55 °C solves it. Ventilation is separately required — ABS and ASA release styrene while printing.
Which filament is best for outdoor use?
ASA. It has ABS's heat resistance with the UV-sensitive butadiene replaced, so it keeps its colour and impact strength in direct sunlight. PETG is acceptable in shade or for short-term outdoor use; PLA is not suitable outdoors at all.
Do I need to dry PLA, PETG and ABS?
All three print better dry, but the urgency differs. PETG is the most moisture sensitive of the three and should be dried at 65 °C for 6 hours if it has been open for more than a few days. PLA needs 45 °C for 4 hours. ABS is the most forgiving, though a wet spool still prints with a rough, pitted surface.