PLA, PETG or ABS? Which one to use in each case
Almost everything printed with FDM can be solved using three materials. This is the short, applied guide: what to use based on where the part will spend its life.
What the failure looks like
This isn't a failure: it's the single decision that determines whether the part will last. Choosing the wrong material leads to parts that warp in the sun or snap on first use.
Causes, most likely first
- 01
Heat
PLA deforms above around 55 °C: it won't survive inside a car in summer.
- 02
Sun and outdoor use
PLA becomes brittle with UV exposure; ASA is the ultimate outdoor material.
- 03
Mechanical stress
PLA is rigid but brittle: it holds load until it snaps suddenly.
- 04
Food contact
No FDM material is truly food-safe without a food-safe varnish: the layer lines trap bacteria.
Step-by-step fix
PLA for decorative parts and visual prototypes
Best finish, easiest to print, most dimensionally stable. Indoor use with no heat.
PETG for general-purpose functional parts
Tougher, resists up to 75 °C, handles weather reasonably well. It's the sweet spot for 70% of functional parts.
ABS/ASA for heat and outdoor use
High thermal resistance and good performance in sunlight (ASA). Requires an enclosure and ventilation.
TPU when flexibility is needed
Gaskets, stoppers, cases, shock absorbers.
Fiber-reinforced for extra rigidity
PETG-CF or PA-CF for technical parts: much stiffer, but they require a steel nozzle.
| Criterion | PLA | PETG | ABS/ASA |
|---|---|---|---|
| Max. operating temperature | ~55 °C | ~75 °C | ~95 °C |
| Outdoor / UV | Poor | Acceptable | Good (ASA) |
| Toughness | Brittle | Tough | Tough |
| Printability | Very easy | Easy | Difficult |
| Surface finish | Excellent | Good | Average |
| Odour / ventilation | No | No | Yes, mandatory |
So it doesn't happen again
- Before printing, ask yourself: where will the part be and what temperatures will it see?
- If in doubt between PLA and PETG for a functional part, choose PETG.
Related questions
Is PLA+ a different material?
No: it's PLA with additives to improve toughness. It still has the same low thermal resistance.
Can I print ABS without an enclosure?
You can try with small parts, but warping and layer delamination will be constant issues. Plus, you need ventilation due to fumes.
Keep reading
Want to go deeper? We have a full article about this on the blog.
What if it isn't worth your time?
Sometimes the part is more urgent than the learning curve. We're a workshop in Viladecavalls: send us the file and we'll print it with the right material and settings.
Still not working?
Tell Marco which printer and material you use and he'll tell you what to change.
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