First layer not sticking? 9 bed adhesion fixes that work
When a first layer won't stick, the cause is almost always a greasy build plate, a nozzle that's too high, a bed temperature that doesn't suit the filament, or a first layer printed too fast. Clean the plate, lower the Z-offset until the lines are squished flat, match the bed temperature and slow the first layer to 20–30 mm/s. Those four fixes solve most adhesion problems on any FDM printer.
- Clean the plate. Wipe with 90%+ isopropyl alcohol; if prints still lift, wash it with warm water and plain dish soap.
- Lower the Z-offset 0.02–0.05 mm until first-layer lines are flat and touching.
- Match the bed to the filament: PLA 55–65 °C, PETG 70–85 °C, ABS 95–110 °C.
- Slow the first layer to 20–30 mm/s.
- Still lifting? Add a 5 mm brim.
What a good first layer looks like
Before you fix anything, know what you're aiming for. Print a single-layer test square (most slicers ship one, or scatter a few 30 mm squares across the bed) and check it against this list:
- Lines are touching, with no gaps you can see through.
- Lines are flat, but still visible. Round, separate lines mean the nozzle is too high. A glassy, featureless sheet means it's too low.
- No ridges, waves or furrows. Those mean the nozzle is ploughing through the plastic (too low).
- It's stuck. You can't flick it off with a fingernail while the bed is hot.
- It's even across the bed. If one corner is perfect and another is stringy, your leveling or mesh is off, not your Z-offset.
1. Clean the build plate (the #1 fix)
One fingerprint is enough to ruin adhesion in that spot, and even a new plate can carry residue from manufacturing and packaging. Clean it before long prints and at the first sign of trouble.
- Let the plate cool and take it off the printer. Handle it by the edges from now on.
- Everyday wipe: 90%+ isopropyl alcohol on an unscented paper towel. Prusa recommends this as the routine degreaser. Skip anything made for skin; lotion-style additives leave oils behind.
- Deep clean when adhesion fades: warm water and a few drops of plain dish soap. Scrub with a soft sponge (a plastic brush gets into textured plates), then rinse well. Bambu Lab recommends this as the main method for textured PEI, because alcohol can just spread oils around in the texture.
- Dry with a clean paper towel and put it straight back on the printer.
- Try the water test. On a clean plate, rinse water spreads into a thin, even film. If it beads up into droplets, there's still oil on it.
Go easy on acetone. Never use it on textured or satin powder-coated PEI; it damages the surface. On a smooth PEI sheet, Prusa allows an acetone wipe once or twice a month to restore grip, but not right before printing PETG, which will then bond too well.
2. Set the Z-offset correctly
Z-offset is the gap between the nozzle and the bed on the first layer. Too high and the plastic is laid on top of the bed instead of pressed into it, so it never grabs. Too low and the nozzle smears and scrapes, which also causes elephant's foot on the bottom of the part.
Printers with automatic Z-offset
Many current printers, including Bambu Lab machines, the Prusa MK4S and CORE One, and the Elegoo Centauri Carbon 2, measure the nozzle height themselves with a load cell or nozzle-contact sensor. If their first layer is wrong, the measurement was usually thrown off:
- Clean the nozzle tip. A blob of old plastic on it gets measured as "bed."
- Clean the plate, then re-run the printer's full calibration or bed leveling.
- If your printer offers it (for example Live Adjust Z on Prusa), nudge the offset down slightly during a test print. Prusa's advice: a little lower for grip, but don't over-squish.
Printers with a probe or manual leveling
- Heat the bed and nozzle to printing temperature. Parts expand when hot, so a cold calibration is off by a few hundredths of a millimetre.
- Home the printer and move the nozzle to the bed centre.
- Do the paper test. Lower the nozzle until a sheet of ordinary printer paper drags slightly but still slides.
- Print a first-layer test and fine-tune live in 0.01–0.02 mm steps until it looks like the checklist above. If you're unsure, lean slightly toward more squish.
- Save the new offset so the next print uses it.
On Marlin printers with a BLTouch-style probe (common on Ender 3 upgrades), babystep while printing, then save:
M290 Z-0.02 ; babystep the nozzle 0.02 mm closer while the first layer prints
M851 ; report the current probe Z-offset
M851 Z-1.45 ; set a new probe Z-offset (example value, use your own)
M500 ; save to EEPROMOn Klipper printers that use the probe as the Z endstop:
SET_GCODE_OFFSET Z_ADJUST=-0.02 MOVE=1 ; 0.02 mm closer, live during the print
Z_OFFSET_APPLY_PROBE ; afterwards, fold the adjustment into the probe z_offset
SAVE_CONFIG ; write it to printer.cfg (restarts Klipper)Klipper printers with a dedicated Z endstop use Z_OFFSET_APPLY_ENDSTOP instead. More detail in bed leveling and Z-offset.
3. Match bed temperature to the filament
Too cold and the first layer never bonds; too hot and the base softens and flares. Start in the middle of the range and move 5 °C at a time.
| Filament | Bed temperature | Notes |
|---|---|---|
| PLA | 55–65 °C | Much hotter softens the base and can cause elephant's foot. |
| PETG | 70–85 °C | Bonds very hard to smooth PEI; use glue stick as a release layer or a textured plate. |
| ABS | 95–110 °C | Needs an enclosure for anything bigger than small parts. |
| ASA | 100–110 °C | Same as ABS: enclosure, low fan. |
| TPU 95A | 40–60 °C | Can bond too well to smooth PEI; textured PEI needs no glue. |
| Nylon | 70–90 °C | Glue stick or a Garolite plate; dry the filament first. |
| Polycarbonate (PC) | 110–120 °C | Heated enclosure and a glue separation layer. |
On large beds, let the plate soak at temperature for a few minutes before printing so the whole surface, not just the sensor spot, is up to heat.
4. Slow down the first layer
The first layer is the one place where slow always wins. Fast printers often default to around 50 mm/s for layer one, which is fine once everything else is dialled in. While you're troubleshooting:
- First-layer speed: 20–30 mm/s.
- First-layer height: 0.2–0.25 mm on a 0.4 mm nozzle, even if the rest of the print is finer. A thicker first layer is far less sensitive to tiny bed variations.
- First-layer line width: about 120–125% of the nozzle (0.5 mm on a 0.4 mm nozzle) for more contact area.
- Part-cooling fan off for the first layer or few. Cold air on a fresh first layer makes it shrink and let go.
5. Re-run bed leveling and the bed mesh
Beds and plates move: shipping, a nozzle crash or simply relocating the printer can tilt or bend things. If the first layer is good on one side and bad on the other, re-level before touching anything else.
- Auto-leveling printers: run a full bed leveling from the printer's calibration menu, or enable bed leveling in the print dialog for the next job.
- Klipper printers: run
BED_MESH_CALIBRATE, ideally in your start macro after homing so you get a fresh mesh every print. - Manual-knob printers (older Ender 3-style beds): tram all four corners with paper while the bed is hot, then re-check the centre.
- Same bad spot every time? The plate itself may be bent, or a magnet sheet may have a bubble under it.
6. Stop drafts and cold air
- Drafts pull heat out of the first layer. An open window, a fan or an air-conditioning vent blowing across the bed is enough to lift PLA and PETG corners. Move the printer or shield it.
- A cold room or garage makes everything harder to stick. Warm the room or give the bed a longer heat soak.
- Direct sunlight heats one side of the bed unevenly. Shade the printer.
If corners stick at first and then peel up a few layers later, that's warping, not adhesion. See warping and curling.
7. Add a brim (or a raft, as a last resort)
A brim is a flat ring of extra lines attached to the base of the part. It adds grip exactly where small, tall or sharp-cornered parts tend to let go.
| Option | Size | When to use it |
|---|---|---|
| Brim ears / mouse ears | Small discs at the corners | Only the corners lift. OrcaSlicer has a "Mouse ear" brim type; Bambu Studio can paint brim ears onto corners. |
| Narrow brim | 3–5 mm | Small or tall PLA and PETG parts. Peels off cleanly. |
| Wide brim | 8–10 mm | ABS, ASA, nylon and other warp-prone plastics. |
| Raft | Full under-layer | Only when the bed surface itself is the problem (damaged or very uneven). Wastes filament and leaves a rough bottom. |
A brim-to-object gap of about 0.1 mm (OrcaSlicer and Bambu Studio call it "Brim-object gap") keeps it easy to snap off.
8. Use the right surface and adhesion aid
The plate surface and the filament together decide whether you need anything extra. Sometimes the aid is there to make a print release, not stick.
| Surface | PLA | PETG | ABS / ASA | TPU | Nylon / PC |
|---|---|---|---|---|---|
| Smooth PEI | None | Glue stick as a release layer | Glue stick as a separation layer | Glue stick as a release layer | Glue stick |
| Textured PEI | None (brim for tiny parts) | None | Glue stick as a separation layer | None | Glue stick |
| Glass | Glue stick or hairspray | Glue stick | Glue stick | Glue stick | Glue stick |
| Garolite (G10/FR4) | Rarely used | Rarely used | Rarely used | Rarely used | A popular surface for nylon |
"Glue stick" means an ordinary PVA glue stick, applied as a thin, even layer on a cold plate. It washes off with warm soapy water. Don't use superglue or other adhesives on a PEI sheet.
Your last PETG print ripped a flake out of your smooth PEI sheet when you removed it. What should you do next time?
PETG can bond to clean smooth PEI so strongly that it tears the coating. A thin PVA glue layer acts as a separator; Prusa recommends textured or satin sheets for PETG. Acetone would make the bond even stronger.
9. Refresh or replace worn parts
If you've worked through everything above and prints still won't stick, the hardware is suspect.
- Worn smooth PEI gets glossy and loses grip after a year or two of heavy use. Prusa suggests lightly sanding it with 600–1000 grit paper to expose fresh PEI, or flipping to the other side.
- Worn textured plates show shiny bald patches where the coating has gone. Flip the plate or replace it.
- A worn or partly clogged nozzle under-extrudes, which shows up first on the first layer. Brass nozzles wear quickly with abrasive filaments (carbon fibre, glass fibre, glow-in-the-dark); use hardened steel for those. See clogged nozzle.
First layer diagnosis table
| What you see | Likely cause | First fix |
|---|---|---|
| Round, separate lines with gaps between them | Nozzle too high | Lower the Z-offset 0.02–0.05 mm |
| Glassy, smeared or rippled surface; nozzle scraping | Nozzle too low | Raise the Z-offset 0.02–0.05 mm |
| Lines stick, then peel up during the first layer | Dirty plate or bed too cold | Wash the plate; raise the bed 5 °C |
| Bottom of the part flares outward | Over-squished or bed too hot | See elephant's foot |
| Good on one side, bad on the other | Bed not level or mesh out of date | Re-run bed leveling |
| Corners lift after several layers | Warping (shrinkage, drafts) | Brim, stop drafts, enclose for ABS/ASA |
| Nothing comes out for the first few centimetres | Nozzle not primed | Add a skirt or prime line |
| Print sticks too well and damages the sheet | PETG or TPU on smooth PEI | Glue stick as a release layer |
Frequently asked questions
Why won't my first layer stick to the bed?
The usual causes are a greasy build plate, a nozzle set too high, a bed temperature that doesn't suit the filament, or a first layer printed too fast. Clean the plate, lower the Z-offset until the lines are squished flat and touching, set the bed to the filament's range and slow the first layer to 20–30 mm/s.
Should I use glue stick on a PEI bed?
Not for PLA on clean PEI. Use a thin layer of PVA glue stick as a release layer when printing PETG or TPU on smooth PEI, because they can bond so hard they tear the sheet, and as a separation layer for ABS, ASA, nylon and PC.
What bed temperature should I use for PLA?
55–65 °C is the standard range for PLA. Much cooler and parts can release mid-print; much hotter and the base softens, which can cause elephant's foot.
How do I know if my Z-offset is right?
Print a single-layer test square and look at it closely. Lines should be flat and touching with no gaps but still visible; round, separate lines mean the nozzle is too high, and a glassy, smeared or rippled surface means it is too low.
Related articles
Sources & further reading
- Prusa Knowledge Base — First layer issues
- Prusa Knowledge Base — Smooth steel sheet (care and acetone use)
- Bambu Lab Wiki — Textured PEI plate cleaning guide
- Ellis' Print Tuning Guide — First layer squish
- Marlin documentation — M851: XYZ probe offset
- Klipper documentation — Probe calibration
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