Guide
PLA vs PETG: which should you actually use?
Here's the rule that answers 90% of cases:if the part's job is to look good, print PLA. If its job is to survive something — force, heat, weather — print PETG.Everything below is detail on top of that rule.
| PLA | PETG | |
|---|---|---|
| Ease of printing | Easiest of all filaments | Moderate — needs tuning |
| Strength style | Stiff, but snaps suddenly | Flexes and absorbs impact |
| Heat resistance | Sags around 60 °C | Solid to roughly 75 °C |
| Outdoors / UV | Fades and weakens | Good — holds up for seasons |
| Water contact | Fine briefly, degrades slowly | Very good |
| Surface finish | Excellent, matte or silk | Glossy, slightly more stringing |
| Colors available | Endless | Good, but a smaller range |
| Price per kg | $ | $ (nearly identical) |
| Enclosure needed | No | No |
The strength question, honestly
Spec sheets say PLA has higher tensile strength, and it's true — clamped in a lab rig, PLA resists a steady pull slightly better. But that's not how parts fail in your house. Parts fail by being dropped, twisted, over-tightened, or flexed one time too many. PLA fails those moments suddenly: it holds, holds, then snaps clean. PETG bends, whitens, and gives you a warning — and usually just springs back. That's why hooks, brackets, clips, and anything structural should be PETG, while the numbers still technically call PLA "stronger."
Heat: the summer-car test
PLA softens around 60 °C. A car dashboard in the sun passes 70 °C easily — PLA phone mounts come out of a summer car as modern art. PETG stays rigid to roughly 75 °C, which covers cars, sunny windowsills, and warm workshops. (For things mounted outdoors in direct sun year-round, one step further — ASA — is worth a look, but that needs an enclosure.)
What PETG demands in return
PETG's toughness isn't free. It strings more — fine wisps between travel moves that PLA barely produces. It drinks moisture from the air, so a spool left out for a week prints crackly and rough (drying guide). And it bonds so hard to smooth PEI build plates that it can rip the coating off — use a textured plate or a swipe of glue stick as a release layer. None of this is difficult; it's just more rules than PLA's "press print."
The verdict
Keep both on the shelf. PLA is your default — decorative prints, prototypes, gifts, and everything while you're learning. PETG is your "this one matters" material — parts that grip, hold, live outside, or sit in the heat. Not sure which your project is? TheFilament Pickerasks five questions and tells you, with starting temperatures included.
Common questions
Is PETG stronger than PLA?
It depends what 'strong' means. PLA is actually stiffer and resists steady loads slightly better — but it fails suddenly, snapping like a cracker. PETG bends and gives before breaking, which is what you want in parts that get dropped, flexed, or repeatedly used. For most real-world 'strong parts', PETG wins.
Why are my PETG prints stringy?
PETG strings more than PLA by nature — it's a stickier, more fluid material at printing temperature. Wet filament makes it dramatically worse: PETG absorbs moisture from the air within days. Dry the spool (55 °C, ~6 hours), then lower nozzle temperature in 5 °C steps until strings fade.
Can PETG damage my print bed?
Yes, one specific way: PETG bonds so aggressively to smooth PEI sheets that removing a print can tear the coating off the bed. Use a textured plate for PETG, or wipe a thin layer of glue stick on a smooth plate first — there it acts as a release layer, not an adhesive.
Should a beginner start with PLA or PETG?
PLA, clearly. It forgives every beginner mistake PETG punishes: no drying needed at first, minimal stringing, prints on any machine out of the box. Switch to PETG when a specific part fails from heat, force, or weather — then you'll also know exactly why you're switching.