First layer not sticking: how to fix bed adhesion
2026-08-22
Why the first layer will not stick
The first layer is the foundation of the whole print. If it does not bond, the part comes loose halfway through and hours of work plus metres of filament go in the bin. The good news: the list of causes is short, and almost all of them take ten minutes to check. Here they are, in the order worth checking.
1. Bed levelling and Z-offset
The nozzle must travel at the same height over the whole surface. On a tilted bed the layer sticks on one side and floats in the air on the other.
- Heat the bed to its working temperature before levelling: metal changes shape slightly as it warms.
- Go around the adjustment points twice: tightening one corner shifts its neighbour.
- Set the Z-offset so the first-layer line is slightly squashed. A round strand just lying on the bed means the nozzle is too high; a translucent smear you can see the bed through means it is too low.
A probe does not replace manual levelling: it compensates for bumps, but a basic tilt is better taken out with the screws.
2. Bed temperature per material
A cold bed is the second most common cause. The working ranges from our material guides:
PLA holds even on an unheated bed, but heat forgives small levelling errors. PETG barely sticks at all without a heated bed. ABS is its own case: besides a 100-110 °C bed it needs an enclosure, no draught and part cooling switched off, or the corners will lift no matter how good the adhesion is.
3. A clean plate
Finger grease is the invisible enemy of adhesion. Take a few parts off with bare hands and the plate carries a film that 3D printing plastic simply will not grip.
- Wash the plate now and then with warm water and dish soap; wipe it with isopropyl alcohol between prints.
- Hold the plate by the edges, not by the print area.
4. First-layer speed
Lay the first layer slowly, 20-25 mm/s. At high speed the melt has no time to press into the surface, so the line sits on top instead of bonding. After that you can speed up - only the first layer is critical.
5. Brim
A brim is a few rings of first-layer perimeter around the part. It adds contact area and anchors the corners that cooling pulls upward. For ABS it is close to mandatory: as it cools, ABS contracts by roughly 0.6-0.8 %, and the corners let go first. After printing, the brim snaps off by hand or comes off with a knife.
Glue stick: two different jobs
For PLA and ABS a glue stick is an adhesion booster: a thin layer on glass or a smooth plate helps when the surface is worn or the part stands on a small footprint.
With PETG the job is reversed. PETG sticks to the bed too well: on bare glass it can tear a chunk out of the surface along with the part. A thin layer of glue stick here works as a release agent, not as glue - the part pops off cleanly and the bed survives.
If nothing helped
Check the filament itself: damp plastic hisses in the nozzle and bonds worse - each material guide lists its drying regime. The material helper can match a plastic to your job, and if a question remains, write to us.
Frequently asked
- Why does my print come off the bed halfway through?
- Most often it is shrinkage: the plastic cools, contracts and pulls the corners up. A brim, the right bed temperature and no draught help, and for ABS an enclosure.
- How do I know my Z-offset is right?
- The first-layer line should be slightly squashed. A round strand that peels off easily means the nozzle is too high; a translucent smear with the nozzle scraping means it is too low.
- Do I need a glue stick for PLA?
- On clean PEI or a textured plate, usually not. It helps on glass and smooth surfaces. For PETG the glue stick plays the opposite role - a release agent, so the part does not damage the bed coating.
- What bed temperature does PETG need?
- 70-90 °C. On an unheated bed PETG barely sticks at all. Details are in the PETG guide.