Getting a Perfect First Layer with PETG
PETG asks for the opposite of PLA on layer one: more heat, less squish. Press PETG into the plate PLA-style and it climbs back up the nozzle, balls up, and gets dragged across the print. Give it heat and room instead, and it lays down glassy and solid.
Why PETG first layers behave differently
Molten PETG is sticky and elastic. Squished hard against the plate, it doesn’t spread into a wide flat line like PLA — it clings to the nozzle tip, accumulates, and eventually deposits itself as a blob somewhere it shouldn’t. This is why experienced PETG printers describe the ideal first layer as “laid onto” the plate rather than pressed into it, and why a slightly higher first-layer height or gentler squish works better than PLA-style smashing.
The numbers that matter
Bed: 70 °C on textured PEI, up to 80 °C for stubborn spools. PETG’s bond to PEI builds steeply with temperature. On SuperTack the ceiling is 60 °C; the Cool Plate is marked unsupported for PETG entirely.
Filament settings → Filament (bed temperature row for your plate)Nozzle: hotter on layer one. The stock profile already runs the first layer at 245 °C against 250 °C for the rest of the print; a further +5 °C helps weak bonding. (Interesting aside: several vendors do the same trade differently — QIDI’s PETG baseline drops the later layers to 245 °C on layer one while Sovol’s runs the first layer hottest of all at 265 °C.)
Filament settings → Filament → Nozzle temperature (initial layer)Speed: 20 mm/s, and fan off early. The profile keeps the fan off for the first 3 layers — early airflow chills the sticky melt before it wets the plate. Slow beats squished with PETG, every time.
The classic PETG first-layer mistakes
- Chasing adhesion with squish. If lines ball around the nozzle, you are too close/too much flow — back off. Heat, not pressure, is PETG’s adhesive.
- Printing on bare smooth PEI. PETG welds to it and takes coating with it at removal. Always a thin glue film as a separator on smooth plates; textured PEI needs nothing.
- Ignoring moisture. Wet PETG crackles and lays a pitted, foamy first layer that grips badly. Dry
8 h at 65 °C; if the first layer is bubbling, no setting will save it. - Greasy plate. PETG is the most grease-sensitive of the common materials. Dish soap wash whenever adhesion fades.
Reading a PETG first layer
A good PETG first layer looks glossy and slightly rounded — not the matte, flat sheet PLA gives. Faint gaps between lines that would signal trouble in PLA are acceptable in PETG if the lines themselves are well bonded to the plate; the second layer closes them. Blobs, drag marks and balled-up material mean too much squish, too much flow (0.95 is the stock flow ratio — run flow calibration for generic spools), or a wet spool. When adhesion itself is the problem rather than looks, continue with PETG bed adhesion; for the general craft, the first layer guide and calibration walkthrough.
Frequently asked questions
Why does PETG ball up around the nozzle on the first layer?
Molten PETG is sticky and elastic — squished hard against the plate PLA-style, it doesn’t spread into a flat line but clings to the nozzle tip, accumulates and eventually drops as a blob. The ideal PETG first layer is laid onto the plate rather than pressed into it: back off any manual z-offset, use a gentler squish, and rely on heat, not pressure, for adhesion.
What bed and nozzle temperatures does PETG need for the first layer?
Run the bed at 70 °C on textured PEI, up to 80 °C for stubborn spools — PETG’s bond to PEI builds steeply with temperature. On SuperTack the ceiling is 60 °C, and the Cool Plate is unsupported for PETG. The stock profile prints the first layer at 245 °C nozzle; a further +5 °C helps weak bonding. Keep the first layer at 20 mm/s with the fan off for the first 3 layers.
Are small gaps in a PETG first layer okay?
Yes — faint gaps between lines that would signal trouble in PLA are acceptable in PETG if the lines themselves bond well to the plate; the second layer closes them. A good PETG first layer looks glossy and slightly rounded, not matte and flat like PLA’s. Blobs, drag marks and balled-up material are the real warning signs: too much squish, too much flow (stock flow ratio is 0.95) or a wet spool — dry 8 hours at 65 °C.
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- First Layer Not Sticking: Causes and Solutions — Bambu Lab Wiki
- Filament Drying Recommendations — Bambu Lab Wiki
- OrcaSlicer vendor profiles — SoftFever/OrcaSlicer (GitHub)