Which material should you choose for 3D printing? PLA, PETG, ASA, nylon and TPU in practice
A comparison of FDM printing materials by heat resistance, toughness and UV stability. A practical guide to choosing PLA, PETG, ASA, nylon or TPU.
For most functional parts the safest choice is PETG: it handles roughly 68 °C, it is tough and it is affordable. Use PLA only for display models, because it softens at around 55 °C. ASA belongs outdoors thanks to its UV stability and 93 °C heat resistance, nylon suits abrasion-prone parts, and TPU is for anything that has to flex.
In FDM printing, material is the single decision with the biggest impact on whether a part survives in service. Below you will find concrete numbers rather than adjectives.
Quick comparison of FDM materials
| Material | Heat resistance | Toughness | Suitable outdoors | Typical use |
|---|---|---|---|---|
| PLA | 55 °C | average | no | mock-ups, display models, exhibition pieces |
| PETG | 68 °C | high | short term | functional parts, enclosures, production jigs |
| ASA | 93 °C | high | yes, UV stable | outdoor brackets, parts for cars |
| Nylon (PA) | up to 190 °C* | high | limited | gears, bushings, abrasion-prone parts |
| TPU (flex) | flexible, 95 Shore A hardness | elastic deformation | limited | gaskets, damping pads, flexible elements |
The heat resistance figures come from filament manufacturer Prusa Polymers for specific branded materials (PLA, PETG, ASA). They are meant for comparison between materials, not as a guaranteed value for every brand.
*The 190 °C figure applies to Prusament PA11 Carbon Fiber, a carbon-filled nylon. Unfilled nylons are considerably less resistant. For a specific order we will always tell you which type of nylon we are planning to use.
PLA: when it is enough and when it will let you down
PLA is the cheapest and easiest material to print, but its heat resistance is only 55 °C. In practice that means a PLA part will deform in a car parked in the sun, next to a window, or anywhere near a motor.
The manufacturer also rates it as a material with no susceptibility to warping and average toughness. It prints accurately and holds its dimensions, but under impact it cracks before it bends.
Choose PLA for a presentation mock-up, for checking shape and dimensions, for an exhibition model, or for a part that will spend its life sitting indoors under no load. For anything that has to move, carry or get warm, pick something else.
PETG: the default choice for functional parts
PETG is the material we recommend most often. Its heat resistance is 68 °C, the manufacturer rates its toughness as high and its warping tendency as low. That combination handles the vast majority of everyday jobs.
Compared to PLA it has one property that decides things in service: under impact it bends rather than snaps. For a jig that falls off a bench, or an enclosure someone presses on, that is the difference between a scratch and scrap.
We use it for electronics enclosures, assembly jigs, brackets, housings and most spare parts. It is also the most sensible starting point for small-batch production, where you need consistent quality at a reasonable price.
ASA: the only one of the five that truly survives outdoors
ASA is the successor to ABS and was developed precisely to last outside. The Prusa Knowledge Base sums it up in one sentence: compared to ABS, "ASA is more UV resistant, warps less, and doesn't smell as much" (Prusa Knowledge Base).
The difference shows on parts after a few months in the sun. ABS parts yellow and become brittle under prolonged UV exposure, while ASA holds up in those conditions far longer (Prusa). On top of that its heat resistance is 93 °C, the highest among common materials that do not require special printing techniques.
We choose ASA for facade brackets, outdoor electronics housings, parts for cars, and anywhere the part sees sun or rain.
Nylon (PA): when the part wears against something
Nylon is the choice for places where two parts rub against each other. Gears, plain bearings, guides, pulleys. It is strong and exceptionally abrasion resistant, which neither PETG nor ASA can match.
It has two practical drawbacks. It is hygroscopic, meaning it draws moisture from the surrounding air and has to be dried before printing, otherwise the part loses strength and surface quality. And manufacturers recommend an enclosed printer for it (Prusa Filament Material Guide), which shows up in the price.
That is why we use nylon deliberately, when the part has a real mechanical reason for it. For an enclosure or a bracket it is an unnecessarily expensive solution.
TPU: when the part has to flex
TPU is not measured by heat resistance but by hardness on the Shore scale. The common value is 95 A, roughly the hardness of a shopping trolley wheel. To give a sense of what the material takes: the technical data sheet for PolyFlex TPU95 lists elongation at break of 551 ± 24 % to ISO 37 (Polymaker).
In other words, a TPU part can be stretched to more than five times its original length. It is used for gaskets, damping pads, protective sleeves, anti-slip feet and flexible hinges.
If you need a part that gives a little and springs back, TPU is the only sensible option on this list.
How to pick a material in thirty seconds
Work through these questions in order and stop at the first one you answer yes to:
- Does the part need to flex or seal? → TPU
- Will other parts wear against it? → nylon (PA)
- Will it sit outdoors in the sun, or in a car? → ASA
- Does it carry load, run in service, or just need to survive normal handling? → PETG
- Is it only a mock-up to look at? → PLA
This sequence covers most of the briefs that reach us. If you are not sure, describe the environment and the load and we will propose the material.
Material is not the only thing that decides strength
The same part in the same material can be strong or brittle depending on how it is printed. In practice three things decide it.
Part orientation on the bed. An FDM part is built from layers, and it is always somewhat weaker between layers than along them. We therefore orient the part so the main load runs across the layers, not along them.
Infill density. We print anywhere from 5 to 100 % depending on what the part is for. A mock-up is fine at 10 %; a loaded jig goes considerably higher. Infill is also one of the biggest levers on the price of a print.
Layer height. We work in the 0.08 to 0.3 mm range. A lower layer means a finer surface and a longer print; a higher one is faster and cheaper.
We hold an accuracy of ± 0.1 mm, and the maximum size of a single piece is 256 × 256 × 256 mm. Larger parts are split into sections and bonded. Full specifications are on the FDM printing page.
Frequently asked questions
Which material is the strongest? It depends what strong means. For abrasion and mechanical stress nylon is best, for heat resistance ASA (93 °C), for impact resistance PETG. There is no universally "strongest" material, which is why we always ask about the environment and the type of load.
Will a 3D printed part survive in a car? Inside a car parked in the sun, PLA will not: its heat resistance is 55 °C and summer temperatures behind glass routinely exceed it. For parts in cars we choose ASA at 93 °C, or PETG for places out of direct sunlight.
Which material is cheapest? PLA and PETG are the most affordable; engineering materials such as nylon cost more. The difference in material cost is often smaller than the difference in print time, though. Current rates are on our pricing page.
Can a 3D printed part be painted? Yes, but the surface needs preparation. Finishing work such as sanding, bonding or installing threaded inserts is done on request and charged separately.
What if I don't know which material I need? Tell us what environment the part will work in, what load it has to take, and whether it will sit in sunlight. We will propose the material and explain the choice in the quote, which we send within 24 hours.
What if I don't have a 3D model? We can prepare the model from a drawing, a photo or a physical sample. For more on what we need from you, see how to prepare a 3D model for printing, or look at our 3D modeling service.
Leave the material choice to us
Send us a model, or simply describe what the part has to withstand. We will propose the material, the infill density and the print orientation, and within 24 hours you will have a no-obligation quote including a lead time.