PETG is a common choice for functional parts, and polycarbonate is a logical next step when a PETG part has to cope with more heat. Both can be translucent: Polymaker lists 90% light transmission for PolyLite PETG and 89% for PolyLite PC. Where they differ is heat resistance, strength and how much the printer has to do.
Both grades below come from Polymaker's PolyLite line and were tested with the same ISO methods on 100% infill specimens, though the PETG specimens were printed at ambient temperature and the PC specimens in a 90 °C environment. Prusa's material guides add printing and handling notes for its PETG and PC Blend.
PETG and Polycarbonate blends side by side
| Property | PETG | Polycarbonate blends |
|---|---|---|
| Nozzle temperature | 230–260 °C (PolyLite PETG); Prusa: 230 °C first layer, 240 °C after | 250–270 °C (PolyLite PC); Prusa: 275 °C |
| Bed temperature | 70–80 °C (PolyLite PETG); Prusa: 85 °C first layer, 90 °C after | 90–105 °C (PolyLite PC); Prusa: 110 °C first layer, 115 °C after |
| Enclosure and part cooling | Enclosure not needed; fan off to 20% (Polymaker) | Chamber needed at 70–100 °C; fan off (Polymaker) |
| Build surface | PC or textured PEI (Polymaker); Prusa: not on smooth PEI, adhesion may be too strong | Textured PEI, glue when needed (Polymaker); Prusa: not on smooth PEI without glue |
| Heat deflection, ISO 75 (1.8 / 0.45 MPa) | 75 °C / 78 °C | 107 °C / 111 °C |
| Vicat softening (ISO 306) / glass transition | 84 °C / 81 °C | 120 °C / 113 °C |
| Tensile strength, ISO 527 (X-Y / Z) | 50.8 / 42.8 MPa | 69.1 / 52.8 MPa |
| Tensile modulus, ISO 527 (X-Y) | 2116.8 MPa | 2497 MPa |
| Flexural strength, ISO 178 (X-Y) | 69.6 MPa | 106.1 MPa |
| Elongation at break (X-Y / Z) | 8.4% / 3.3% | 4.8% / 2.7% |
| Notched Charpy impact, ISO 179 (X-Y) | 2.6 kJ/m² | 4.1 kJ/m² |
| Light transmission, GB/T 2410 | 90% | 89% |
| Drying and annealing | Dry 65 °C for 6 h (Polymaker); annealing not stated | Dry 75 °C for 6 h; anneal 90 °C for 2 h right after printing (Polymaker) |
| Printing difficulty | Prusa: easy to print, suitable for beginners | Prusa: very hard to print, mainly for advanced users; PC Blend much easier than other PCs |
Property values come from Polymaker's PolyLite PETG and PolyLite PC technical data sheets (ISO methods, 100% infill specimens), with printing and handling guidance from Prusa's PETG and polycarbonate articles.
Heat: the main reason to switch
Heat is where the two separate most. Polymaker lists 75 °C heat deflection at 1.8 MPa for PolyLite PETG and 107 °C for PolyLite PC, with Vicat softening at 84 °C and 120 °C. Prusa says PETG suits most exterior uses below 80 °C, and lists strong heat tolerance among PC's strengths.
If a PETG part has softened or sagged in service, PC is a reasonable candidate. If it failed for another reason, such as a crack at a sharp corner, the heat figures alone do not justify the extra printing effort.
Strength and stiffness
PolyLite PC is stronger in every direction Polymaker tested: 69.1 MPa tensile strength in-plane against 50.8 MPa for PETG, 52.8 MPa against 42.8 MPa across layers, and 106.1 MPa against 69.6 MPa in bending. It is also stiffer, with a tensile modulus of 2,497 MPa against 2,117 MPa.
PETG stretches further before breaking (8.4% in-plane against 4.8%), while PC has the higher notched Charpy value (4.1 against 2.6 kJ/m²). Both values are low next to the 18.0 kJ/m² Polymaker lists for PolyLite ABS, so notches and sharp internal corners deserve care with either material.
What polycarbonate asks of the printer
PETG prints without an enclosure, according to Polymaker, and Prusa calls it easy to print. Prusa's cautions for PETG are stringing, weak bridging and strong adhesion that can damage smooth PEI. Polycarbonate needs more: Polymaker lists a 250–270 °C nozzle, a 90–105 °C bed and a 70–100 °C heated chamber for PolyLite PC.
Prusa says PC warps heavily, especially on large parts, recommends a separation layer such as glue on the build sheet, and lists price among its drawbacks. Its tips include avoiding parts that cover the whole bed and using fewer perimeters on large prints, since more perimeters and higher infill increase warping.
Drying and annealing
Polymaker recommends drying PolyLite PETG at 65 °C for 6 hours and PolyLite PC at 75 °C for 6 hours. Prusa says most pure polycarbonates are very hygroscopic and should be stored airtight with desiccant, while its PC Blend absorbs much less.
Polymaker also recommends annealing PolyLite PC at 90 °C for 2 hours right after printing to relieve internal stress, and suggests a heated chamber for large parts. For parts with tight fits, a useful check is to anneal a test piece first and measure it.
Which should you choose?
Choose PETG if…
- The part stays below the 80 °C Prusa gives for most exterior PETG use.
- Your printer is open-frame or has no heated chamber.
- Some stretch before breaking helps; PolyLite PETG elongates 8.4% in-plane against 4.8% for PC.
- Cost and simplicity matter; Prusa lists PC's price among its drawbacks.
Choose Polycarbonate blends if…
- The part must stay rigid near 100 °C, given PolyLite PC's 107 °C heat deflection at 1.8 MPa.
- You need more tensile and bending strength than PETG offers.
- You can hold a 70–100 °C chamber and a 90–105 °C bed.
- You can anneal parts after printing, as Polymaker recommends for PolyLite PC.
Common questions
Is polycarbonate worth it over PETG?
When heat is the problem, often yes: Polymaker lists 107 °C heat deflection at 1.8 MPa for PolyLite PC against 75 °C for PolyLite PETG. If the part stays below about 80 °C, the limit Prusa gives for PETG, PETG is the simpler choice.
Can I print polycarbonate without an enclosure?
Polymaker lists a 70 to 100 °C chamber as needed for PolyLite PC, and Prusa strongly recommends an enclosure. Without one, Prusa suggests centering the part, using a high skirt and a brim, and avoiding parts that cover the whole bed.
Which is clearer, PETG or PC?
Polymaker lists almost the same light transmission for both: 90% for PolyLite PETG and 89% for PolyLite PC (GB/T 2410). Print settings and part thickness will affect clarity more than that one-point gap.
Sources
- PolyLite PETG technical data sheet Polymaker · Checked 2026-11-02
- PolyLite PC 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
- Polycarbonate (PC) Prusa Research · Checked 2026-10-15
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.