Which material should it be?
Two materials, each on the shelf because it’s the best at something. Here’s what they’re like to live with, including the things they’re bad at. Still unsure? Tell us what the part does and we’ll choose for you.
Answer four questions.
We’ll suggest a starting point. Tap any that apply.
PLA
For most indoor objects, PLA is the right answer: rigid, crisp, and available in the most colours.
Price a file in PLASide by side.
Ratings are relative to each other, from our own printing, not a lab. Heat figures are roughly where parts start to soften.
| Property | PLAPolylactic acid | PETGGlycol-modified polyester |
|---|---|---|
| StrengthHow hard it is to snap or crack. | ||
| StiffnessHow little it bends under load. | ||
| FlexibilityHow far it bends and springs back. | ||
| Fine detailHow crisp small features and text come out. | ||
| Heat resistanceSoftens around | 55 °C | 70 °C |
| OutdoorsSun, frost and rain | Indoors only | Sheltered outdoors |
| Food contactAs a printed part | Not food safe | Not food safe |
| Process | Filament (FDM) | Filament (FDM) |
| PriceMaterial only | $0.06/g | $0.07/g |
| Colours |
A straight answer on food safety
No 3D print is food safe as it comes off the printer, whatever the plastic. The tiny ridges between layers hold on to bacteria and can’t be scrubbed clean, and filament colourants aren’t certified for food. A cookie cutter used once and thrown away is fine; a cup, plate or chopping board isn’t. If you need food contact, ask us about coating options, or have it moulded.
PLA
Polylactic acid · $0.06 per gram
The everyday plastic. Rigid, crisp on detail, made from plant starch, and available in the most colours.
- Good for
- Indoor decor, planters with a saucer, desk things, display models and first prototypes.
- Not for
- Anything that sits in a hot car, goes in the dishwasher, lives outdoors or holds a load for months.
- Food contact
- Not food safe as printed. Layer lines trap bacteria and colourants aren’t certified. Fine for a cookie cutter used once.
- Heat
- Starts to soften around 55 °C. Keep it out of hot cars and dishwashers.
PETG
Glycol-modified polyester · $0.07 per gram
Tougher than PLA with a little give, so it bends before it snaps. Shrugs off water and most household chemicals.
- Good for
- Clips, brackets, hooks, kitchen and bathroom parts, planters without a saucer, anything that gets knocked.
- Not for
- Heat above about 70 °C and very fine surface detail. It strings a little, so tiny text comes out soft.
- Food contact
- The raw plastic is used in food packaging, but a printed part isn’t food safe: the layer lines can’t be cleaned properly.
- Heat
- Starts to soften around 70 °C. Fine by a sunny window; not in a hot car.