Materials · Published on 23 October 2026 · By the usi3d team

PLA vs PETG vs ASA vs TPU (plus ABS and nylon): which filament to use for every part

For figures, prototypes and most things that live indoors, PLA. If the part has to take knocks, water or some heat, PETG. Outdoors in the sun or inside a car, ASA (or ABS out of direct sunlight). For parts that need to flex, TPU. And for gears and hinges that rub, nylon. ABS, ASA and nylon want an enclosed printer and ventilation; PLA and PETG print happily on any open-frame machine.

How to choose a filament: three questions first

Before reading any data sheets, answer three questions about your part. What temperature will it face? A mount on a car dashboard in the sun can go past 70 °C; a figure on a shelf never gets near 30. Will it take knocks, bend or rub? Will it live outdoors? Those three answers rule out half the materials.

The fourth question is your printer. PLA, PETG and TPU print well on an open machine. ABS, ASA and nylon shrink as they cool and lift or crack if room air chills one side: they need an enclosed printer, or at least an enclosure.

Filament comparison table

Temperatures are typical ranges for each family; the manufacturer of your spool always has the final say, and it is usually printed on the label. ‘Heat resistance up to’ is roughly where the part starts to deform under load, not its melting point.

The filaments, one by one

PLA: the filament to start with, and for almost everything

It is stiff, barely shrinks, does not smell and gives the best finish of the lot. It prints well at 200-210 °C with the bed at 60 °C and the part fan at 100%. For figures, models, prototypes, desk organisers or cosplay pieces it is the first choice, and the cheapest.

Its limits: it softens at around 55-60 °C (a part left in a car in summer will warp) and it is brittle, snapping rather than bending. PLA+ or tough PLA improves impact resistance while staying easy to print; silk PLA has a sheen and prints a little hotter. If yours snaps during assembly, try printing 5-10 °C hotter and adding a perimeter.

PETG: the all-rounder for functional parts

It survives knocks that would crack PLA, water does not bother it and it copes with around 70-80 °C. It prints on any open printer at 235-245 °C, with the bed at 75-80 °C and the fan at 30-50%. It is the pick for wall brackets, tool boxes, bike parts, planters or anything that gets wet.

It has two quirks. It strings more than PLA: dry the spool and fine-tune retraction. And it bonds so hard to smooth PEI sheets that it can tear a chunk out when you pull the part off: use a textured sheet or a layer of glue stick as a release agent (PETG on smooth PEI guide).

ABS and ASA: for heat and for sunlight

Both handle around 95-100 °C, sand well and are tough. ABS can be smoothed with acetone vapour; ASA is its outdoor cousin, resisting ultraviolet light without yellowing or turning brittle. For a garden hook, a motorbike part or a car vent grille, ASA.

The cost is in the printing: they shrink as they cool, so corners lift and upper layers crack if there is a draught. They need an enclosed printer, a bed at 100 °C and little or no fan. For warping and cracks, the ABS and ASA enclosure guide gathers what the manufacturers recommend.

TPU: when the part has to flex

TPU is rubber-like and close to impossible to break. Its hardness is measured on the Shore A scale: 95A, the most common, is firm like a trainer sole; 82A is a good deal softer and harder to print. Use it for phone cases, gaskets, toy wheels, furniture bumpers or straps.

Print it at 220-230 °C with a warm bed and slowly, between 20 and 40 mm/s on most printers, with minimal retraction. A direct-drive extruder pushes it far better than a Bowden setup, where the soft filament buckles inside the tube. If it jams or wraps around the drive gear, follow the TPU feeding and clogs guide.

Nylon: the toughest and the fussiest

Nylon (PA) resists wear and fatigue like nothing else on this list: gears, living hinges, clamps or parts that flex thousands of times. It wants 250-280 °C, an enclosed printer and glue on the bed.

Its enemy is moisture: it pulls water from the air within hours, and wet nylon gives bubbles, stringing and weak parts. Dry it before every job and print from a dry box (nylon and moisture guide). Carbon fibre-filled versions are stiffer and more stable but wear out brass nozzles, as we explain in when to change your nozzle.

Which filament to use for each part

What about food and drink? No part printed at home is food-safe on its own: the layers leave crevices where bacteria grow, and the nozzle or the colourant can add substances that were never meant for it. For an occasional cookie cutter, keep contact with the dough short, and keep PLA out of the dishwasher.

How to dry and store filament

They all absorb some moisture, some much more than others. A damp spool crackles at the nozzle, strings and makes weaker parts. As a guide, these are the usual drying temperatures in a filament dryer or an oven with reliable temperature control:

• PLA: 45-50 °C for 4-6 hours.
• PETG: 60-65 °C for 4-6 hours.
• ABS and ASA: 70-80 °C for about 4 hours.
• TPU: 50-55 °C for 4-8 hours.
• Nylon: 70-80 °C for 8-12 hours, and nearly always before printing.

Then store spools in airtight bags or boxes with desiccant. The wet filament guide explains how to spot it and dry it without warping the spool.

Choosing filament with AI on usi3d

If you would rather get an answer for your specific part, from today there is Choose the right filament with AI. It runs in your browser and uses no credits.

1. Open your model

   An STL, 3MF, GLB or OBJ, one of the site’s examples, or none at all if you do not have it yet.

2. Say what it is for

   In your own words (‘a hook for the garden hose’) or by ticking a use: keyring, figure, outdoors, car or motorbike, mechanical part, flexible, toy, kitchen or bathroom, among others.

3. Say what it must withstand and which printer you have

   Knocks, heat, sun and rain, water, wear or bending; and whether your printer is an open or enclosed filament machine, or a resin printer.

4. Read the recommendation

   It ranks the materials that suit the part, best first, with what you would notice in use and what each needs when printing. The ones that will not work are listed separately, with the reason.

In the recommendation, materials listed in the usi3d shop link to their spools: there is PLA, PLA+, PETG, ASA and TPU, plus filament dryers, all bought on each retailer’s own website. And to see what your part will cost in the material you choose, use the cost calculator.

Try it on usi3d: Choose the right filament with AI