PETG vs ABS: Which Filament Should You Use?
PETG and ABS are both strong, functional filaments that outperform PLA for mechanical parts. But they have very different printing requirements and trade-offs. Here's how they compare across the properties that actually matter for your project.
Quick comparison
| Property | PETG | ABS | Winner |
|---|---|---|---|
| Tensile strength | ~50 MPa | ~40–50 MPa | Draw |
| Impact resistance | High — bends before breaking | Medium — brittle under sharp impact | PETG |
| Heat deflection temp | ~70–80°C | ~80–100°C | ABS |
| Warping tendency | Low | High — needs enclosure | PETG |
| Fumes | Low — safe in open space | Styrene vapors — needs ventilation | PETG |
| Post-processing | Difficult to sand/paint | Acetone smooth, easy to sand/paint | ABS |
| Moisture sensitivity | Moderate — dry if stringing | Low — relatively moisture stable | ABS |
| Print difficulty | Easy — no enclosure needed | Hard — enclosure + no drafts | PETG |
| Nozzle temp | 230–250°C | 230–260°C | Draw |
| Bed temp | 70–85°C | 100–110°C | PETG |
| Cost | ~$20–25/kg | ~$18–22/kg | Draw |
Print settings: PETG vs ABS
PETG settings
ABS settings
When to choose PETG
- You don't have an enclosure
- You want a functional part with good impact resistance
- The part operates below 70°C
- You need chemical resistance (PETG resists most weak acids and alcohols)
- The part needs to flex slightly without breaking
- You're printing in an enclosed room without dedicated ventilation
- You want food-safe prints (food-safe PETG + food-safe nozzle required)
When to choose ABS
- You have an enclosed printer with ventilation
- The part will be exposed to temperatures above 70°C (car interior, near engines)
- You need to post-process: sand, paint, acetone-smooth, or glue parts together
- You need very stiff, rigid parts that won't creep under load
- You're printing replacement parts for existing ABS products (same thermal expansion)
- You need UV resistance (ABS handles UV better than PETG)
ABS safety: fumes and ventilation
ABS printing releases styrene — a volatile organic compound classified as a possible carcinogen with long-term exposure. This does not mean ABS is dangerous for occasional prints, but it does mean you should take ventilation seriously.
Minimum precautions: print in a well-ventilated space, open a window, and don't sit directly next to the printer for hours. For regular ABS printing: use an enclosure with a HEPA + activated carbon filter, or vent the enclosure exhaust outdoors.
PETG emits far lower levels of particles and VOCs. No special ventilation is needed for occasional PETG printing in a normal room.
PETG vs ABS: layer bonding and strength
Layer adhesion is a key difference between the two materials. ABS has excellent inter-layer bonding in an enclosure — parts can approach injection-molded strength when printed at 250°C with zero fan and a hot chamber. PETG's layer bonding is good but slightly weaker in Z-axis tension.
In practice, PETG parts printed correctly are strong enough for most functional applications. The difference matters most for parts under sustained tensile load along the Z axis — think a printed bolt being pulled straight out of a printed nut, or a clip that's constantly being stressed at the layer line.