What filament should I use? It's the first question most people ask before a custom print, and it's a good one. The material your part is printed in changes how it looks, how strong it is, how it handles heat, and whether it survives life outdoors. You don't need to be a materials scientist to choose well, though. You just need to know what each material is good at.
The quick answer: PLA for looks and prototypes, PETG for parts that have to work, TPU for anything flexible, ASA or ABS for heat and sun, and PA-CF for stiff, strong parts. Not sure? Tell us what the part needs to do and where it will live, and we'll recommend one. You don't need to know the material up front.
What Filament Should I Use for My Project?
PLA: The Everyday Choice
PLA is the most common 3D printing filament, and it earns that spot. It prints easily, captures fine detail, comes in nearly every color, and gives a good surface straight off the printer. It's what we reach for with props, display pieces, and prototypes.
Strengths
- Fine detail
- A huge color range
- The easiest to print reliably
- A good surface right off the printer
Weaknesses
- Brittle under sharp impacts
- Softens in a hot car or direct sun
- Not a good fit for long-term outdoor use
Best for: props, display pieces, prototypes, figurines, and anything indoors that won't take a beating.
PLA also comes in specialty versions. We used glow-in-the-dark PLA for the blade of a prop sword.
PETG: When a Part Has to Work
PETG is what we reach for when a part has to work, not just look good. It's tougher than PLA, handles more heat, and takes impacts better, with a slight gloss that suits functional parts. It prints well without much fuss.
Strengths
- Tough and impact-resistant
- Better heat tolerance than PLA
- Good chemical resistance
- A slightly glossy finish
Weaknesses
- Can string if the settings aren't dialed in
- A bit harder to post-process than PLA
Best for: brackets, enclosures, mechanical parts, and anything that carries load or sits somewhere warm.
TPU: The Flexible One
TPU is rubbery, grippy, and able to bend over and over without cracking. It suits anything that has to absorb impact instead of resisting it, like grips, gaskets, bumpers, and wearables. It takes more care to print, but the results are impressive.
Strengths
- Flexible and elastic
- Absorbs impact well
- A grippy surface
- Good abrasion resistance
Weaknesses
- Slower to print
- Can string if it isn't tuned well
- Not rigid like PLA or PETG
Best for: grips, gaskets, seals, bumpers, and wearable accessories.
ASA: The Outdoor Option
ASA resists UV light, so it holds its color and strength in the sun in a way PLA and PETG don't, and it copes with temperature swings. If a part will live outside, ASA is what we'd suggest first.
Strengths
- Excellent UV resistance
- Good heat tolerance
- Tough and weather-resistant
Weaknesses
- Needs an enclosed printer
- Gives off fumes while printing, so it needs good ventilation
- Warps more than PLA or PETG
Best for: outdoor fixtures, automotive parts, and anything exposed to sun or temperature extremes.
What About ABS, PA-CF, and Other Materials?
Those four cover most jobs, but they aren't the whole list. ABS is tough and heat-resistant like ASA, but it isn't UV-stable, so it suits parts that stay out of the sun. PA-CF is carbon-fiber-filled nylon. It's stiff, strong, and heat-resistant, which makes it a good fit for demanding functional parts. We used it for a replacement RV chair lever.
We work with many more materials than these, so if your project calls for something specific, just ask.
How Do the Materials Compare?
| Material | Strength | Heat Resistance | Flexibility | UV Resistance | Difficulty |
|---|---|---|---|---|---|
| PLA | Medium | Low | Rigid | Poor | Easy |
| PETG | Good | Medium | Slightly flexible | Fair | Easy to medium |
| TPU | Medium | Medium | Very flexible | Good | Medium |
| ASA | Good | High | Rigid | Excellent | Harder |
| ABS | Good | High | Rigid | Poor | Harder |
This is a rough guide. Exact behavior depends on the brand of filament and the print settings.
Frequently Asked Questions
What is the best filament for beginners?
What filament should I use for a functional part?
Do I need to choose a filament when I order?
Can you print in materials that aren't in this guide?
Ready to start? Get in touch and tell us what your part needs to do. Our 3D printing services in Spokane page covers what we offer, and if you're new to FDM, our guide to FDM 3D printing explains how it all works.