First Layer Not Sticking to the Bed? Here's What to Do
Contents
The filament will not grip the bed, it balls up behind the nozzle or the print pulls off the bed at the third layer. The cause is almost always one of five things: bed leveling, the distance between the nozzle and the bed (Z offset), a dirty bed surface, the wrong temperature or a first layer printed too fast. If you check them in the order below, you will usually find the problem within half an hour.
Symptoms
A first layer problem shows up in different ways. Knowing which one you have narrows down the cause:
- The filament does not stick to the bed at all and balls up behind the nozzle.
- Lines are round and separate with gaps between them.
- The print pulls off the bed after a few layers, or the nozzle drags the part along.
- Corners lift. There is a separate guide for this: Warping.
- The nozzle scrapes the bed, no filament comes out or the surface is scratched.
The first two symptoms usually show the nozzle is too far from the bed, and the last one shows it is too close.
What does a good first layer look like?
In a good first layer the lines are slightly squashed, flat and touching each other. When you run a finger over it you feel a smooth surface. There are no gaps between lines, but the nozzle also does not press hard enough to push plastic out to the sides.
| Appearance | Meaning | What to do |
|---|---|---|
| Round, separate lines | Nozzle too high | Lower the Z offset (move the nozzle closer) |
| Flat lines touching each other | Right distance | Leave it alone |
| Translucent, very thin, rough surface | Nozzle too low | Raise the Z offset (move the nozzle away) |
| Good in one place, bad in another | Bed tilted or warped | Level the bed again |
1. Check the bed leveling
If one corner of the bed is higher than the others, the first layer is squashed in one place and hangs in the air in another. Check the level with the paper method: heat the bed and nozzle to printing temperature, move the nozzle over each corner and the middle, and check that an A4 sheet of paper slides with slight drag.
For a step-by-step explanation: How to level the bed
If your printer has an automatic leveling sensor (BLTouch, CR Touch, inductive sensor or load cell), the sensor measures the bed's warp but does not know the offset between the nozzle and the sensor. You set that offset: the Z offset.
2. Adjust the Z offset
Even if the level is right, if the nozzle is slightly away from the bed, the filament is not pressed onto the surface and does not grip. Start the print and, while the first layer prints, change the "Z offset" or "Babystep" setting on the screen in steps of 0.02–0.05 mm. Stop as soon as the lines flatten and touch each other, and save the value.
Details on this setting: Z offset
3. Clean the bed
Even a fingerprint can badly hurt adhesion. Cleaning by surface type:
- Spring steel plate with PEI coating: Wipe with isopropyl alcohol (IPA). Once a month wash it with warm water and dish soap and dry it well. Use acetone only if the manufacturer allows it and only on smooth PEI.
- Glass bed: Clean with IPA or glass cleaner.
- Magnetic "buildtak"-type surface: Wipe with IPA and follow the manufacturer's instructions.
After cleaning, do not touch the surface with bare hands. Hold the plate by its edges.
4. Check the temperatures
If the filament is too cold for the bed, the plastic hardens quickly and lifts. If the bed is too hot, some materials soften and you get elephant's foot. Approximate starting values:
| Filament | Bed | First layer nozzle |
|---|---|---|
| PLA | 55–65 °C | 5 °C above normal |
| PETG | 70–85 °C | 5 °C above normal |
| ABS / ASA | 95–110 °C | Normal |
| TPU | 40–60 °C | Normal |
The values on the filament box always come first. If the room is cold or there is a draft in front of the printer, raising the bed temperature by a few degrees and closing doors helps.
5. Slow down the first layer settings
Check these settings in the slicer:
- First layer speed: 15–25 mm/s. A line printed slowly sits better on the bed.
- First layer height: 0.2–0.3 mm. A thicker first layer tolerates small irregularities in the bed.
- First layer line width: 110–120% of the nozzle diameter (0.44–0.48 mm for a 0.4 mm nozzle).
- Fan: Keep the part cooling fan off for the first 1–3 layers.
6. Helpers that increase adhesion
If the above are right, you usually need nothing extra. Still, for difficult parts:
- Brim: Adds a single-layer border 5–10 mm wide around the part, increasing the contact area. See Brim vs skirt vs raft.
- Adhesive: On a flat glass bed, a thin coat of glue stick works for PLA and PETG. PETG sometimes sticks too much to smooth PEI; on such surfaces the glue acts as a release layer.
- Mouse ears (corner discs): For long, thin parts, adding small discs only at the corners is also effective.
7. If it still will not stick
- The bed may be warped. Hold a ruler edge against the bed and look at it against the light. If the middle is dished or raised, use mesh leveling.
- The filament may be wet. If you hear popping and see bubbly lines, dry the filament.
- Extrusion may be insufficient. If the lines are thin and broken, see the under-extrusion guide.
- The PEI surface may be worn. Shiny, worn areas reduce adhesion. You may need to matte it lightly with fine sandpaper or replace the plate.
Frequently asked questions
Why does the first layer stick on one side but not the other?
The bed is tilted toward one side or the surface is warped. Level the corners again one by one. If the problem continues, use mesh leveling with automatic leveling.
The part sticks during printing but then will not come off. What should I do?
Wait until the bed has cooled. Flexing the spring steel plate slightly will release the part. When printing PETG on smooth PEI, use a thin layer of adhesive to protect the surface, because PETG can pull pieces off the surface.
Do I need to level before every print?
No. If the bed has not been moved and the screws have not loosened, the level holds for weeks. It is enough to check when first layers start to get worse.