Filament 101: PLA, PETG, and ABS
Filament is the raw material your printer melts and deposits. Picking the wrong one for your use case is one of the most common beginner mistakes. The good news: the right material for a first printer is almost always PLA.
The mental model
Think of filament materials like paint types: watercolour, oil, acrylic. Each has a different working temperature, drying time, and strength once cured. You wouldn’t use watercolour to paint outdoor furniture. You wouldn’t use oil paint for a quick sketch. Same logic applies to filament.
The three materials you need to know
| PLA | PETG | ABS | |
|---|---|---|---|
| Nozzle temp | 200–215°C | 230–245°C | 230–250°C |
| Bed temp | 55–65°C | 70–85°C | 90–110°C |
| Enclosure needed | No | No (helps) | Yes |
| Common use | Prototypes, decorative, learning | Functional parts, water-resistant | Heat-resistant, structural |
| Common failure | Warps if bed too cold; brittle | Stringing; moisture-sensitive | Severe warping; toxic fumes if unenclosed |
PLA (Polylactic Acid)
PLA is the easiest filament to print. It prints at low temperatures, sticks well to a heated PEI bed, doesn’t warp much, and doesn’t require an enclosure. It’s made from corn starch and is technically biodegradable — though it takes industrial composting conditions to actually break down.
The catch: PLA has a low heat resistance. It softens around 60°C, which means it will deform in a car on a hot day, or anywhere near a heat source. It’s also more brittle than PETG or ABS under impact.
Use PLA for: decorative prints, organizers, anything that won’t see heat or mechanical stress.
PETG (Polyethylene Terephthalate Glycol)
PETG is PLA’s more capable sibling. It’s tougher, slightly flexible, and more heat-resistant (around 80°C). It’s good for functional parts like brackets, clips, and anything that needs a bit of give under load.
The trade-offs: PETG strings more than PLA. It’s also moisture-sensitive — store your spool in a sealed bag with desiccant, or you’ll get bubbling and poor layer adhesion. Print temperatures are higher, so make sure your hot end can handle it (most can).
Use PETG for: functional parts, anything that needs impact resistance, outdoor-ish use.
ABS (Acrylonitrile Butadiene Styrene)
ABS is strong, impact-resistant, and heat-tolerant (up to 100°C+). It’s what LEGO bricks are made of. It’s also the hardest of the three to print.
ABS warps — badly. Without an enclosure to maintain a consistent ambient temperature, the part will curl off the bed mid-print. It also produces fumes that are unpleasant and potentially harmful. You need an enclosure with ventilation.
Use ABS for: parts that see real heat or impact, enclosure-mounted hardware, anything that needs to live in a car.
Beginner recommendation: skip ABS until you’ve nailed PLA and PETG.
The practical flowchart
- Start with PLA. It’s forgiving, cheap, and covers 80% of beginner use cases.
- Switch to PETG when you need something tougher or slightly heat-resistant, and once you’ve dialled in your first-layer settings.
- Add ABS only when you have a specific need for high heat resistance and you’ve already got an enclosure.
What can go wrong
- Using moisture-damaged filament — PETG and ABS absorb moisture from the air. If your prints are bubbling, snapping, or producing inconsistent extrusion, the filament may be wet. Dry it in a food dehydrator at 65°C for 6–8 hours.
- Storing filament open on a shelf — PLA tolerates this better than PETG/ABS, but ideally store all filament in sealed bags or airtight containers with desiccant.
- Printing ABS without an enclosure — the base of the print will cool too fast, contract, and peel off the bed. This isn’t a settings problem; it’s a physics problem. The fix is an enclosure.
- Mixing up temperature settings — if you load PETG and forget to change the temperature from your PLA profile, you’ll under-extrude or clog. Always double-check the material in the slicer before printing.