How to Print PETG: Settings That Work
Starting settings
- Nozzle 230 to 245 C (drop 5 to 10 C if stringy)
- Bed 75 to 85 C
- Layer fan 30 to 60 percent
- Retraction direct drive: 1 to 2 mm at 35 mm/s
- Retraction Bowden: 5 to 7 mm at 40 mm/s
- First layer speed 20 mm/s, height 0.2 mm
- Travel speed 150 to 200 mm/s
Stringing: the most common complaint
PETG strings because it stays sticky in the melt zone longer than PLA. Three fixes that compound: lower temp 5 to 10 C, increase retraction by 0.5 mm at a time, enable 'wipe' and 'coasting' in your slicer. Most PETG stringing clears at 230 to 235 C.
Bed adhesion: PETG sticks too well to glass
On bare glass or PEI, PETG often grips so hard the print rips chunks of the surface off. The fix: gluestick a thin layer between the print and the surface, every print. The gluestick is the release agent. Alternatively, use a textured PEI sheet and let the print cool fully before removing.
Layer fan
PETG benefits from less aggressive cooling than PLA. 30 to 60 percent fan gives a good surface finish without compromising layer adhesion. Overhangs may need higher fan for that section; modern slicers handle this automatically.
Bridges and overhangs
PETG bridges noticeably worse than PLA. For prints with long unsupported spans, either add support or design the geometry differently. Where PLA bridges 30 mm cleanly, PETG starts to sag at 15 mm.