Polyethylene Terephthalate (PET) is a semi-rigid material commonly used to make plastic water bottles. It has one primary variant, called PETG, which has a modified glycol component. PETT is also available, which typically results in slightly more transparent prints. No PET variants suffer from much cooling-related warping and so can be actively cooled.
- Bed Temperature: 75-90 °C
- Heated Bed: recommended
- Build Surface: Painter’s tape, Glue stick
- Extruder: Temperature 230-250 °C
- Part Cooling Fan: Required
Best Practices and Tips
A heated build platform is recommended for PETG filaments. You can often get PETG prints to stick to unheated surfaces, but print bed adhesion is improved when the bed is heated. A heated bed also reduces the chance of any warping issues.
Stringing is a common issue for PETG that must be resolved with precise calibration of your printer’s retraction distance and speed settings. Some slicing software packages offer a related setting called “coasting,” which reduces the pressure in the nozzle just before it gets to the end of a line where it would retract.
When printing PETG at higher temperatures, blobbing becomes more of an issue. This can also be addressed with the use of a coasting setting. Alternatively, an “extra restart distance” setting can also help, especially in combination with coasting.
The glossy surface of PETG makes it easier to separate prints from rafts while maintaining the surface finish of the print.
If you’re facing warping issues, disabling the cooling fan for the first few layers can help, especially for larger prints.
- Glossy, smooth, and transparent finish
- Adheres well with minimal warping
- Doesn’t smell much when printed
- Not great for bridging
- Prone to stringing
This information should give you a great starting point for PETG printing. Have you got any specific projects you’re planning to use PETG or its variants for? Let us know down below.