PLA vs PETG vs ASA: which should you choose?
Three plastics cover most of what people print. They cost about the same, so picking the right one comes down to where the part will live and what it has to put up with.
The quick answer
- PLA for things that live indoors and need to look good. Models, gifts, organisers, display pieces.
- PETG for parts that do a job. Brackets, clips, shed and garden bits, anything that gets wet or knocked.
- ASA for anything in the sun or heat. Car, boat, caravan and outdoor fittings, and parts you want to paint.
Side by side
| PLA | PETG | ASA | |
|---|---|---|---|
| Price | Cheapest | About the same as PLA | A little more |
| Heat | Softens from about 55 to 60 °C | Fine to about 70 to 75 °C | Fine to about 90 to 95 °C |
| Full sun | No. Goes chalky and brittle | OK in part sun | Yes, for years |
| Hot car | No, it sags | Not on a dashboard | Yes |
| Knocks and drops | Snaps rather than bends | Tough, flexes a little | Tough |
| Water | Fine with cold water | Very good | Very good |
| Detail and finish | Sharpest detail | Slightly glossy, softer edges | Matte |
| Sand and paint | Yes | Not well | Yes, very well |
Heat figures are typical softening points for these plastics. A printed part under load will start to give before that.
PLA: the everyday plastic
PLA prints the cleanest and comes in the widest range of colours and finishes, including matte and silk. It's stiff and holds sharp detail, so it's the right pick for anything decorative. Its weak spot is heat. Leave a PLA part on a car dashboard in an Australian summer and it will droop. In full sun it slowly goes chalky and brittle. Indoors, out of the heat, it lasts for years.
Read more: PLA 3D printing.
PETG: the working plastic
PETG is what most functional parts should be printed in. It's tougher than PLA and bends a little before it breaks, so clips and snap fits survive. It's very good with water and fine in a hot shed. It costs about the same as PLA. The trade-offs: it's a bit glossy, edges aren't quite as crisp, and it doesn't sand or paint well. If you need even more toughness, PCTG is its stronger cousin.
Read more: PETG 3D printing.
ASA: made for the sun
ASA is in the same family as ABS, the plastic used for car trim and outdoor fittings, with UV stabilisers added. It keeps its colour and strength in full sun and holds its shape at temperatures that would wreck PLA or PETG. It's also the best of the three for sanding, filling and painting. It costs a little more and large flat parts need care to stop warping, which we handle when we set the print up.
Read more: ASA 3D printing.
Still not sure? Ask these three questions
- Will it sit in the sun or a hot car? Yes: ASA.
- Will it get knocked, bent, clipped or wet? Yes: PETG.
- Neither, and it needs to look good? PLA.
If it has to bend or seal, none of these is right. Look at flexible TPU. If it has to be very stiff or take real heat, a carbon or glass fibre grade may be the answer. See all materials.
Whatever you pick, we check every order before it prints. If the material doesn't suit the part, we'll tell you before anything is made.