First layer not sticking or stuck too hard? Causes and fixes
The first line the printer lays down, the prime line or the skirt, usually tells you the cause. A round strand that lifts off with a fingernail points to a nozzle that is too high or a dirty sheet. A flattened strand with ridges along the edges points to a nozzle that is too low. Failure in just one area of the bed points to grease or leveling.
How to recognize it
- The strand drags around corners and curls up behind the nozzle instead of lying down.
- Lines come out round, with gaps between them, and peel off with a fingernail.
- One area of the sheet sticks and another doesn't, sometimes in the shape of a fingerprint.
- The part breaks loose mid-print and the nozzle keeps printing into the air, building a nest of spaghetti.
If the part sticks at first and the corners lift after a few layers, that is a different problem: see the guide to warping and lifting corners.
Causes, from most to least likely
| Cause | Typical sign | First thing to do |
|---|---|---|
| 1. Grease and fingerprints | sticks in one area, fails in another | wash the sheet with dish soap |
| 2. Nozzle too high | round strands with gaps between lines | lower the nozzle in small steps |
| 3. Wrong plate selected in the slicer | started after you swapped sheets | pick the right plate and re-slice |
| 4. Bed too cold for the material | PETG or ABS lets go; PLA lets go in a cold room | raise the bed 5 °C |
| 5. First layer too fast or fan on | lets go on curves and small parts | slow it down and turn the fan off |
| 6. Bed out of level | one side sticks, the other doesn't | redo the leveling |
| 7. Worn sheet | shiny patches where nothing sticks | scuff it lightly or replace it |
| 8. Not enough plastic coming out | thin lines across the whole bed | dry the filament, check the nozzle |
How to fix it, step by step
1. Wash the sheet, don't just wipe it with alcohol
The routine from the Bambu Lab cleaning guide: wet the sheet, spread dish soap with no moisturizers, scrub with a sponge or plastic brush, rinse and dry with a paper towel. From then on, handle the sheet by its edges. The test is water: on a clean sheet it forms a continuous film; on a greasy one it beads up. On a textured sheet that's only a clue: what settles it is printing again in the same spot after washing.
Between prints, Prusa recommends 90% or stronger isopropyl alcohol on a cold sheet. On textured PEI, Bambu Lab prefers soap, because alcohol can just spread the grease into the texture. Never use acetone on textured sheets; on smooth ones, only if the maker allows it (Prusa allows it once in a while, Bambu Lab does not). Pages checked November 2026.
2. Get the nozzle height right
The setting is called Z offset, or Live Adjust Z on Prusa printers. Change it a few hundredths of a millimeter at a time while watching the skirt: a more negative value brings the nozzle closer. The right spot gives flat lines that touch each other and feel smooth. Prusa warns against making up for poor adhesion by over-squishing: a nozzle that is too low clogs and can mark the sheet.
Bambu Lab printers measure the height themselves, but they depend on the plate you pick in the slicer: with the textured plate selected, the printer lowers the nozzle slightly more (0.02 mm in the official A1 profile, 0.04 mm in the P1S one). If the slicer has a different plate selected, the nozzle ends up high and the bed may run at the wrong temperature.
3. Use the right bed temperature for the material
Ranges from Bambu Lab's filament table for PEI plates, checked November 2026. The exact value for your spool is on its label.
| Material | Bed (PEI) | Nozzle | On smooth PEI |
|---|---|---|---|
| PLA | 45 to 65 °C | 190 to 240 °C | prints directly, no glue |
| PETG | 60 to 80 °C | 240 to 270 °C | glue stick as a release layer |
| ABS and ASA | 90 to 100 °C | 240 to 280 °C | directly or with glue; large parts need an enclosure |
| TPU | 35 to 45 °C | 200 to 250 °C | glue as a release layer |
Some makers ask for more: Prusament PETG uses 85 °C for the first layer and 90 °C after that. If a material won't stick, Prusa suggests raising the bed 5 to 10 °C; in a room below 20 °C, Bambu Lab suggests 10 °C more. Too hot a bed with PLA and PETG spreads the base out, which is called elephant's foot.
4. A slower first layer with the fan off
- Speed: Prusa suggests about 75% of normal speed for the first three layers. Cura's profile for Creality printers uses 20 mm/s for the first layer.
- Fan: off for the first three layers, as Bambu Lab recommends for PLA, PETG and TPU.
- Thicker first layer: if adhesion keeps failing, Bambu Lab suggests a 0.25 mm first layer with 0.5 mm line width on a 0.4 mm nozzle.
The settings are Initial layer and No cooling for the first in Bambu Studio and OrcaSlicer; First layer speed and Disable fan for the first in PrusaSlicer; Initial Layer Speed and Initial Fan Speed in Cura.
5. Smooth or textured: each needs its own care
Textured PEI leaves a textured bottom, releases the part once it cools and takes PETG without glue. A small part touches only a little of the texture: if it lets go, add a brim or use the smooth sheet, which Prusa recommends for parts with a small contact area.
Smooth PEI gives a glossy bottom and grips PLA well. With PETG and TPU, the bond can be so strong that the part tears pieces of PEI off when you remove it. That is why Prusa asks for a thin layer of glue stick, applied to a cold sheet, only where the part will sit. Here the glue is there to help the part release, not to make it stick harder.
6. Brim, skirt or raft: when they help
- Skirt: an outline a few millimeters away from the part. It doesn't help adhesion, but it shows whether the height is right before the part begins.
- Brim: a one-layer flange attached to the base. The force holding a part down is roughly proportional to its contact area, Bambu Lab notes, so a brim saves small parts and tall, thin ones.
- Raft: a multi-layer base under the part. It costs more material and time and leaves a rough bottom; it makes sense on an uneven bed or a bed without PEI.
7. Manual or automatic leveling
For manual leveling, heat the bed and nozzle, slide a sheet of printer paper (about 0.1 mm) between them at the four corners and the center, and adjust until you feel light drag. Go around a second time, because moving one corner shifts the others. With automatic leveling, a sensor measures the shape of the bed and compensates for it, but it does not set how hard the strand is squished (that is still the Z offset), and it does nothing about a dirty sheet.
When it sticks too hard
Only call it "too hard" with the sheet cold: a warm part always feels glued down. If it's still hard to remove once fully cooled, check in this order:
| What it might be | How to confirm | What to do |
|---|---|---|
| Wrong plate in the slicer | Compare the plate named in the slicer with the one on the printer. If they differ, that's the first suspect. | Pick the installed plate and slice again: it changes the bed temperature and, on Bambu Lab printers, the nozzle height. |
| Nozzle too low | Look at the first line: squashed, with ridges and plastic squeezed out to the sides, confirms it. A smooth, flattened line rules it out. | On Bambu Lab printers, run the calibration again. On machines with manual adjustment, raise the Z offset by hundredths of a millimeter. |
| PETG on smooth PEI | It happens with this pair: PLA on the same sheet releases normally. | Use glue stick as a release layer if the sheet's maker recommends it. With this pair, the part can pull off the coating. |
To remove the part, flex only a flexible, cold sheet and avoid metal scrapers. How hard it feels isn't proof of a low nozzle on its own: confirm with the first line.
How to keep it from coming back
- Handle the sheet by its edges and only remove parts once they have cooled, by flexing the sheet.
- Wash the sheet when water starts beading up on it again.
- Check the plate type in the slicer every time you swap sheets.
- Change one setting at a time, starting from the maker's profile. This and other habits are in the guide to common beginner mistakes.
What a failed first layer costs
An example, with stated assumptions: a 120 g PLA part that takes 6 hours, using the calculator's reference values (PLA at $20/kg; 120 W with electricity at $0.17/kWh; a $600 printer with a 6,000-hour useful life and $0.05/h of maintenance). A machine hour comes to $0.17: $0.02 of electricity, $0.10 of wear and $0.05 of maintenance. Assuming filament is used evenly over the print:
| When the failure shows up | Filament | Machine and power | Total |
|---|---|---|---|
| In the first few minutes (5 g) | $0.10 | almost nothing | $0.10 |
| Breaks loose in hour 2 (40 g) | $0.80 | $0.34 | $1.14 |
| Turns to spaghetti until the end (120 g) | $2.40 | $1.02 | $3.42 |
Add 10 minutes of your time to clean up and restart, at $30 an hour: another $5.00. At US prices your time costs more than the plastic, which is the best argument for washing the sheet and watching the skirt go down before you walk away. To build these losses into your prices, the calculator has a failure reserve.
Frequently asked questions
Can I use glue stick to make PLA stick better?
You can, but on clean PEI at the right height PLA doesn't need it: Prusa recommends glue for PETG, ABS, ASA, nylon, PC and flexibles. If PLA only sticks with glue, the real cause (grease or a high nozzle) is still there. Never use superglue on the sheet.
The part is stuck too hard and won't come off. What now?
Let the sheet and part cool down completely, then flex the sheet; most parts pop off that way. Forcing it with a metal scraper can scratch or tear the coating. If it was PETG on smooth PEI, use glue as a release layer next time.
My textured sheet lost its grip even after washing. Can it be fixed?
Often, yes. Bambu Lab suggests scuffing it lightly with fine sandpaper or steel wool and cleaning off all the dust; Prusa suggests the rough side of a dry kitchen sponge or 400 to 600 grit sandpaper, followed by isopropyl alcohol. If the coating has worn through to bare metal, replace the sheet.
Why do only small parts come loose?
They touch the sheet over a small area, and tall, thin parts also get bumped by the nozzle at high speed. A brim, a slower speed and, if you can, the smooth sheet fix most of these cases.
Do I need to recalibrate after changing the nozzle?
Yes. Prusa asks you to run the first layer calibration again whenever the sensor is replaced or the extruder is taken apart. On printers that probe the bed before printing, leave that step turned on for the first print after the swap.