PLA, PETG or TPU: which filament to use

Updated October 22, 2026

The short answer

PLA for almost everything. PETG if the part will sit in the sun, near heat or hold hot drinks. TPU if you need it to be flexible, like a stamp or a case.

PLA: the easiest

It's the filament almost everyone starts with: it prints easily, doesn't smell, doesn't warp as it cools and comes in countless colors. It's ideal for keychains, signs, figures, terrain models and lithophanes.

Its weak point is heat: it starts to soften around 60 °C. A PLA part inside a car in the sun, or a coaster under a freshly poured cup, can warp.

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PETG: tougher

It's more heat resistant (it softens around 80 °C), more flexible and less brittle than PLA. It's the one for coasters, outdoor parts, keychains that live in the car and anything that takes knocks.

It's a bit harder to print: it needs more temperature and can leave thin strings between parts. A few retraction tests usually fix that.

TPU: the flexible one

It's a rubber-like material. The most common is TPU 95A, flexible but firm. It's the best choice for stamps because it picks up ink evenly, and also for cases, bumpers and parts that bend.

It prints slowly and with little retraction. On printers with the filament motor far from the nozzle (Bowden type) it's harder; on direct-drive printers it's easier.

Reference temperatures

These are common ranges; always check what your brand's box says, because it varies between manufacturers:

• PLA: nozzle 190 to 220 °C, bed 50 to 60 °C.
• PETG: nozzle 230 to 250 °C, bed 70 to 85 °C.
• TPU: nozzle 210 to 230 °C, bed 40 to 60 °C, low speed.

Which one to use with each converter

• QR keychain or sign: PLA, in two colors. Coaster for hot drinks: PETG.
• Lithophane: white PLA. Relief: a light PLA, so the shadows show.
• Name keychain: PLA; PETG if it lives in the car.
• Terrain model: a light PLA.
• Stamp: TPU; PLA works but picks up less ink.

Frequently asked questions