Three filaments cover 90% of what desktop printers make: PLA, PETG and ABS. Pick right and printing is easy; pick wrong and you fight warping, stringing or parts that snap. Here is the honest version of when to use each — including the trade-offs spec sheets gloss over.
The short answer
- PLA — default for decorative prints, prototypes, toys, anything indoors. Easiest to print, sharpest detail, weakest against heat.
- PETG — functional parts: brackets, outdoor items, containers. Tougher and heat-resistant, slightly harder to print cleanly.
- ABS — high-heat, high-abuse parts: car interior pieces, enclosures, anything you will sand or acetone-smooth. Needs an enclosed printer and ventilation.
Side by side
| PLA | PETG | ABS | |
|---|---|---|---|
| Nozzle temp | 190–220 °C | 230–250 °C | 240–270 °C |
| Bed temp | 25–60 °C | 70–85 °C | 95–110 °C |
| Enclosure | No | Recommended for big parts | Required |
| Strength | Stiff but brittle | Tough, slightly flexible | Tough, impact-resistant |
| Heat resistance | ~55 °C (softens in a hot car) | ~75 °C | ~95 °C |
| UV / outdoor | Poor | Good | Fair (ASA is better) |
| Ease of printing | Easiest | Moderate (strings, sticks hard to PEI) | Hardest (warps, fumes) |
What the spec sheets don’t tell you
PLA’s real weakness is time and temperature, not strength. Fresh PLA is stiffer than ABS on paper. But leave a loaded PLA bracket under tension for months, or a print on a car dashboard in summer, and it creeps and sags. Decorative? PLA forever. Structural? Look further.
PETG sticks too well. Print it directly on a bare PEI sheet at full bed temperature and you can rip the coating off. Use a textured plate or a layer of glue stick as a release agent, and dial first-layer squish back. PETG also loves moisture — if prints come out stringy and crackly, dry the spool at 65 °C for four to six hours.
ABS wants a box and a window. Warping is managed with an enclosure and a hot bed — but styrene fumes are the bigger issue. Print ABS in a ventilated space or a printer with a filtered enclosure, never in a bedroom. If you want ABS’s toughness with less drama, ASA prints similarly and handles UV better.
What about recycled filament?
Recycled PLA and PETG have improved fast — good spools now print within a few percent of virgin material’s strength, at lower cost and footprint. The keys are a trusted producer with tight diameter tolerance (±0.03 mm or better) and proper drying. It is a subject close to home: everything in the M3D shop is printed from recycled polymer, and we have written about why recycled beats new. With desktop recyclers now arriving — see Creality’s M1 and R1 — the loop is closing for home printing too.
Bottom line
Start with PLA and stay there until a print fails from heat or force. Move to PETG when parts need to survive the real world. Reach for ABS (or ASA) only when you have the enclosure and airflow to do it right — and whatever you print with, dry your filament. Half of all “bad filament” is just wet filament.
M3Dstore
Writer at M3D — exploring how 3D printing changes the way we learn, make and live.
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