PETG first layer problems show up a few ways: the layer drags under the nozzle, beads up, leaves gaps, or bonds so hard it chips the sheet on the way off. PETG wants a warm bed and a gentle first-layer squish, so a cold bed, an unlevel sheet, or a nozzle pressed too close are the usual causes. Bambu’s first-layer guide and the Prusa PETG page both start there.
A bad first layer fails the whole print, so fix it before the part grows tall. Work the list in order and reprint a single PETG layer after each change.
Per the Prusa PETG page, PETG wants a bed near 80 to 90 C, and it dislikes being mashed flat the way PLA can take.
Where the fault comes from
| Likely cause | Fix | Severity |
|---|---|---|
| Bed too cold | Set the bed to 80 to 90 C, the range PETG needs to bond. | hi |
| Bed not level | Level for a light paper drag at all four corners and the center. | hi |
| Nozzle too far, Z-offset too high | Lower the Z-offset a touch so the first layer presses into the sheet. | md |
| Nozzle too close | Raise the Z-offset a hair, since PETG hates being squished hard. | md |
| Dirty sheet | Wipe the sheet with isopropyl alcohol, and add a glue stick on smooth PEI. | md |
| Wet PETG | Dry the spool at 60 to 65 C, then reprint. | lo |
Start with these fixes
Print a flat one-layer PETG square and watch how it lays down, then work top to bottom and reprint after each step.
Raise the bed
Set the bed to 80 to 90 C so the PETG has the heat it needs to bond.
Level the bed
Heat the bed, then set a light paper drag at all four corners and the center.
Set the Z-offset
Lower it a touch if the layer floats, or raise it a hair if the PETG mashes and drags.
Clean the sheet
Wipe the sheet with isopropyl alcohol, and add a glue stick on smooth PEI as a release aid.
Deeper fixes when the quick ones fall short
When heat and level do not fix the layer, the sheet and the filament are next.
Slow the first layer
Drop the first layer speed so the PETG has time to bond before it cools.
Try a textured sheet
Textured PEI grips PETG better than smooth glass and releases cleaner.
Dry the PETG
If the layer looks rough or pops, dry the spool at 60 to 65 C and reprint.
How PETG differs
PETG wants a warmer bed than PLA, near 80 to 90 C versus 60 C, or it will not bond. It also dislikes a hard first-layer squish, so a nozzle pressed too close drags the PETG and smears it, where PLA would just flatten. PETG can bond so hard to smooth PEI that it chips the sheet, so a glue stick works as a release agent there. ABS needs an even hotter bed and an enclosure, but PETG usually behaves with heat and a clean sheet.
Mistakes that ruin the PETG first layer
A few choices trade one problem for another.
Avoiddo not
- Printing PETG on a 60 C PLA bed temperature.
- Squishing the first layer too hard, which drags and smears PETG.
- Peeling a PETG print off smooth PEI with no release aid, which can chip the sheet.
- Changing bed temp, level, and Z-offset at once.
Key takeaways
- PETG first layers fail from bed temp, level, or the nozzle gap.
- Set the bed to 80 to 90 C, level it, and keep the squish gentle.
- Use a glue stick on smooth PEI as a release aid.
- PETG wants a warmer bed than PLA and hates a hard mash.
For the will-not-stick version, the PETG not sticking guide goes deeper, 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- 01Bambu Lab PETG Usage Guide (wiki): PETG bed and first layeraccessed 2026-06-29Tier 1
- 02Bambu Lab Wiki: First layer not sticking (plate, level, Z-offset)accessed 2026-07-09Tier 1
- 03Prusa Knowledge Base: PETG (bed and first layer)accessed 2026-07-09Tier 1