Summary for the time-pressed
PETG is the default for most functional mechanical parts. ABS is lighter and more machinable. ASA is the right choice for outdoor and UV applications.
Indoor, moderate load → PETG. Outdoor or UV exposure → ASA. Need to machine afterwards → ABS.
Technical comparison
| Property | PETG | ABS | ASA |
|---|---|---|---|
| Service temperature | até ~80°C | até ~100°C | até ~100°C |
| UV resistance | Poor | Poor | Excellent |
| Chemical resistance | Good | Moderate | Good |
| Printability | High | Moderate | Moderate |
| Enclosure required | No | Yes | Recommended |
| Impact resistance | High | High | High |
| Machinability | Moderate | Good | Good |
| Fume emission | Low | High (styrene) | Moderate |
| Relative cost | € | € | €€ |
PETG — the versatile material
PETG is currently the most popular material for functional FDM parts. Good toughness, chemical resistance, and low moisture absorption.
When to choose PETG: structural supports, machine components, threaded parts, functional prototypes.
Limitations: degrades under UV; service temperature limited to ~80°C under continuous load.
ABS — the classic for technical parts
ABS is lighter than PETG, handles slightly higher temperatures and is excellent for post-processing. Acetone dissolves ABS and can be used to smooth surfaces.
When to choose ABS: parts to be machined, components to be glued, lightweight indoor parts.
Limitations: emits styrene fumes — requires ventilation and enclosure; degrades quickly under UV.
ASA — for outdoor use
ASA was developed as a UV-stable alternative to ABS. Shares similar mechanical properties but with exceptional resistance to UV radiation and weathering.
When to choose ASA: outdoor parts, signage, automotive equipment, any application with direct sun exposure.
Limitations: higher cost than ABS; also emits fumes and benefits from an enclosure.
Quick decision table
| Use case | Recommended material |
|---|---|
| Indoor structural support | PETG |
| Outdoor / UV part | ASA |
| Part to be machined | ABS |
| Fluid contact | PETG |
| Temperature > 80°C | ABS ou ASA |
| Fast low-cost prototype | PETG |
| Outdoor automotive part | ASA |