PETG warping is what happens when a PETG print shrinks as it cools and pulls its corners off the bed. The edges curl up, and in a bad case the whole part pops loose. Bambu’s warping guide traces it to a bed that is too cold or dirty, no adhesion aid, or a draft that cools one side too fast.
PETG sits between PLA and ABS for warping. It warps more than PLA but far less than ABS, so a warm, clean bed and a brim are usually enough.
Per the Prusa PETG page, PETG wants a bed near 80 to 90 C to hold, much warmer than PLA needs.
The causes, ranked
| Likely cause | Fix | Severity |
|---|---|---|
| Bed too cold | Set the bed to 80 to 90 C, the range PETG needs to stay stuck. | hi |
| Bed dirty or wrong sheet | Clean the sheet with isopropyl alcohol, and use PEI or a glue stick as a release aid. | hi |
| No brim | Add a brim so the first layer has a wider, stickier footprint. | md |
| Drafts | Move the printer out of airflow so one side does not cool faster than the other. | md |
| Nozzle too low temp | Raise the nozzle a little so the first layer bonds hotter. | lo |
First fixes to try
Print a small PETG part with wide corners, then work top to bottom and reprint after each step.
Raise the bed
Set the bed to 80 to 90 C, the range PETG needs to grip the sheet.
Clean and prep the sheet
Wipe the sheet with isopropyl alcohol, and add a glue stick on smooth PEI so the PETG releases clean.
Add a brim
Turn on a brim so the first layer has a wider footprint that resists lifting.
Block drafts
Keep the printer out of open airflow, since a cool draft on one side lifts that corner.
When quick fixes are not enough
When the bed and the brim do not hold the corners, the first layer setup is next.
Raise the nozzle temp
Add a few degrees to the nozzle so the first layer bonds hotter to the sheet.
Slow the first layer
Drop the first layer speed so the PETG has time to bond before it shrinks.
Use a textured sheet
A textured PEI sheet grips PETG better than smooth glass for warp-prone parts.
How PETG differs
PETG warps more than PLA because it prints hotter and shrinks more as it cools, but it warps far less than ABS or ASA, so it rarely needs an enclosure. The fix is almost always a warm bed, 80 to 90 C, plus a clean sheet and a brim. Wet PETG warps a little more too, since the moisture changes how it lays down, so dry the spool if the warp comes with popping.
Mistakes that invite the warp back
A few choices lift the corners right back up.
Avoiddo not
- Printing PETG on a 60 C PLA bed temperature.
- Running the part fan from layer one, which cools the base too fast.
- Skipping the brim on a wide, flat PETG part.
- Changing bed temp, brim, and fan in one pass.
Key takeaways
- PETG warps when it shrinks and pulls its corners off the bed.
- Set the bed to 80 to 90 C, clean the sheet, and add a brim first.
- PETG warps more than PLA but far less than ABS.
- Change one thing and reprint the same part.
For the general version, the warping guide covers any filament, and the PETG hub covers the material in depth.
Related guides
Related
More in this area
Cross-reference
Sources & methodology
3 citations · reviewed 2026-07-10- 01Prusa Knowledge Base: PETG (bed temperature and adhesion)accessed 2026-07-09Tier 1
- 02Bambu Lab Wiki: Warping, falling off, collapsingaccessed 2026-07-09Tier 1
- 03All3DP: 3D print warping causes and fixesaccessed 2026-07-09Tier 2