PETG and ABS both turn up in functional parts such as brackets, housings and fixtures, but they ask different things of the printer. PETG prints on an open machine with a moderate bed temperature. ABS shrinks more as it cools, so it needs a warm enclosure and gives off fumes that call for ventilation.
To keep the comparison like-for-like, the numbers come from one supplier, Polymaker, whose PolyLite PETG and PolyLite ABS data sheets use the same ISO test methods. Prusa's material guides add printing settings and handling notes. Other brands will differ, so confirm against the data sheet for your spool.
PETG and ABS side by side
| Property | PETG | ABS |
|---|---|---|
| Nozzle temperature | 230–260 °C (PolyLite PETG); Prusa: 230 °C first layer, 240 °C after | 245–265 °C (PolyLite ABS); Prusa: 255 °C |
| Bed temperature | 70–80 °C (PolyLite PETG); Prusa: 85 °C first layer, 90 °C after | 90–100 °C (PolyLite ABS); Prusa: 100 °C, usable 80–110 °C |
| Enclosure | Not needed (Polymaker; Prusa enclosure guide) | Needed (Polymaker); Prusa says the printer should be inside an enclosure |
| Heat deflection, ISO 75 (1.8 / 0.45 MPa) | 75 °C / 78 °C | 98 °C / 100 °C |
| Tensile strength, ISO 527 (X-Y / Z) | 50.8 / 42.8 MPa | 33.4 / 29.7 MPa |
| Tensile modulus, ISO 527 (X-Y) | 2116.8 MPa | 2246.6 MPa |
| Elongation at break (X-Y / Z) | 8.4% / 3.3% | 17.9% / 3.1% |
| Notched Charpy impact, ISO 179 (X-Y) | 2.6 kJ/m² | 18.0 kJ/m² |
| UV and outdoor use | Prusa: suitable for most exterior use below 80 °C; UV resistance not stated | Prusa: yellows and becomes more brittle outdoors |
| Fumes and ventilation | Not stated in Prusa's PETG article | Prusa: potentially dangerous styrene fumes; ventilate the room |
| Drying | 65 °C for 6 h (Polymaker) | 70 °C for 6 h (Polymaker) |
| Finishing | Prusa: smoothing needs dichloromethane, a lab-only solvent | Prusa: acetone vapor smoothing and gluing |
Property values come from Polymaker's PolyLite PETG and PolyLite ABS technical data sheets (same ISO test methods, 100% infill specimens), with printing and safety guidance from Prusa's PETG, ABS and enclosure articles.
Heat resistance
Polymaker lists heat deflection temperatures of 75 °C for PolyLite PETG and 98 °C for PolyLite ABS at the 1.8 MPa ISO 75 load. Prusa's PETG article says PETG parts suit most exterior uses below 80 °C, and its ABS article lists good high-temperature resistance among ABS's strengths.
If the part will run in the 75 to 95 °C range, such as near a motor or inside a hot enclosure, that gap matters. Heat deflection is still a test-bar figure, so compare the expected service temperature with the exact grade's data and allow a margin for load and wall thickness.
Strength and impact
The two materials trade strengths. PolyLite PETG has the higher tensile strength, 50.8 MPa in-plane and 42.8 MPa across layers, against 33.4 MPa and 29.7 MPa for PolyLite ABS. Stiffness is similar. ABS is the tougher of the two under a sharp blow: Polymaker lists a notched Charpy value of 18.0 kJ/m² for ABS and 2.6 kJ/m² for PETG, and ABS stretches about twice as far in-plane before breaking.
A part that carries a steady pull, such as a hook or a bracket, may suit PETG. A part that gets dropped or struck may suit ABS. Polymaker presents its values for comparison rather than design, so test the real part in its printed orientation.
Printing and the room
PETG prints on an open-frame machine. Prusa's enclosure guide groups it with PLA as a low-temperature filament with negligible shrinkage during printing. Prusa does recommend a textured or satin sheet for PETG, because it can bond hard enough to damage smooth PEI.
ABS needs more control. Prusa lists significant warping, recommends a bed of at least 100 °C and an enclosure, and warns of potentially dangerous styrene fumes, so the room also needs ventilation without drafts across the print. Prusa's PETG article does not discuss printing fumes.
Outdoor use and finishing
Prusa's ABS article says outdoor ABS parts yellow and become more brittle over time. Its PETG article lists water and humidity resistance and recommends PETG for indoor and outdoor mechanical parts, though it gives no UV rating. Prusa's ABS article lists the lack of UV resistance as a drawback compared with ASA.
ABS is the easier material to smooth: Prusa notes acetone vapor gives a glossy finish and acetone also glues ABS. Smoothing PETG requires dichloromethane, which Prusa says is for trained lab staff only.
Which should you choose?
Choose PETG if…
- You print on an open-frame machine or in a room with limited ventilation.
- The part carries steady tension, where PolyLite PETG's higher tensile strength helps.
- The part sees water, humidity or outdoor conditions below about 80 °C, as Prusa describes.
- You want a functional part without managing enclosure temperature and warping.
Choose ABS if…
- The part must keep its shape above PETG's range, up toward the 98 °C heat deflection temperature Polymaker lists for PolyLite ABS.
- The part will be dropped or struck, where ABS's higher impact value matters.
- You want acetone smoothing or acetone welding.
- You have an enclosed printer and good ventilation.
Common questions
Is PETG or ABS stronger?
In Polymaker's PolyLite data, PETG has higher tensile strength in both directions, while ABS has a much higher notched impact value and elongation. Which is "stronger" depends on whether the part is pulled steadily or hit.
Which handles more heat?
ABS. Polymaker lists 98 °C heat deflection for PolyLite ABS against 75 °C for PolyLite PETG at 1.8 MPa.
Can I print ABS on the same printer as PETG?
Often, if the printer reaches the temperatures in the table. Prusa recommends an enclosure and a bed of at least 100 °C for ABS, plus a well-ventilated room because of styrene fumes.
Sources
- PolyLite PETG technical data sheet Polymaker · Checked 2026-11-02
- PolyLite ABS technical data sheet (V5.5) Polymaker · Checked 2026-11-02
- PETG Prusa Research · Checked 2026-10-15
- ABS Prusa Research · Checked 2026-10-15
- Enclosure guidepost Prusa Research · Checked 2026-10-16
This comparison summarizes the cited documentation; it is not a lab test. Properties vary by brand, grade, print settings and orientation, so check the data sheet for the exact product you buy.