Filament Types Explained — PLA, PETG, ABS, ASA, TPU and Nylon
What each filament is actually good at, what it needs from your printer, and when to reach for it.
Most people print PLA for a year, hit a wall where PLA is not good enough, and then buy the wrong replacement. Here is the map.
PLA — the default, and a better material than its reputation
Prints at 200–220 °C on a 60 °C bed, on any printer, in any room, with no enclosure. It is stiff, dimensionally accurate, comes in every colour and finish imaginable, and is the easiest material in existence to get a good surface on.
Its weaknesses are specific rather than general: it softens around 55–60 °C, which means a car dashboard in summer will deform it, and it is brittle under sudden impact. For indoor parts that do not get hot, PLA is genuinely excellent and there is no reason to feel you have outgrown it.
Use it for: almost everything, until something specific stops you.
PETG — the sensible upgrade
Prints at 230–250 °C on an 80 °C bed. Tougher than PLA, far less brittle, holds up to around 75 °C, and resists water and many chemicals. It is the natural choice for functional parts, outdoor items and anything that will be dropped.
The trade-off is surface finish. PETG strings, it is fussier about cooling and retraction, and it sticks to smooth PEI plates too well — use a textured plate or a glue-stick release layer, or you will take a chunk out of your build surface.
Use it for: brackets, enclosures, outdoor parts, anything mechanical.
ABS and ASA — the ones that need an enclosure
Prints at 240–260 °C on a 100 °C bed, in a warm, still chamber. Without one, ABS warps off the plate and delaminates in layers. This is not a tuning problem you can slice your way out of — it is physics, and it is why enclosed printers exist.
ABS handles about 100 °C and machines, sands and acetone-smooths beautifully. ASA is ABS with UV resistance, and is the correct choice for anything that lives outside permanently.
Both emit styrene and ultrafine particles while printing. Ventilate the room, or use a printer with filtration, and do not run them in a bedroom.
Use it for: car parts, outdoor fittings, anything that lives above 70 °C. See the Qidi Q1 Pro or Bambu P1S.
TPU — flexible, and slower than you expect
A rubbery filament, sold by shore hardness (95A is common and forgiving; 85A is much softer and much harder to print). It needs a direct-drive extruder — Bowden setups turn flexible filament into a compressed spring — and it needs to be printed slowly, often 30 mm/s or less, with retraction dialled right down.
Use it for: phone cases, gaskets, wheels, vibration dampers, grips.
Nylon (PA) and carbon-filled blends — the engineering tier
Nylon is tough, self-lubricating, and superb for gears, hinges and living joints. It also absorbs water from the air voraciously — a spool left out overnight will hiss and foam on the nozzle the next day. Nylon demands active drying, not just storage.
Carbon-fibre-filled variants (PA-CF, PET-CF, PPS-CF) add stiffness and dimensional stability, and are abrasive enough to destroy a brass nozzle in a few hundred grams. A hardened nozzle is mandatory.
These want high temperatures — often 280–320 °C — and a heated chamber. The Qidi Plus 4 and Bambu H2D are built for this; most printers are not.
Use it for: load-bearing mechanical parts, gears, jigs, tooling.
The rule that covers all of it
Every filament above PETG on this list has the same three requirements: heat, a hardened nozzle, and dry filament. Get those wrong and every material will fail in ways that look like a broken printer.
Buy a dryer before you buy exotic filament. It is the cheapest reliability upgrade in the hobby.