A print usually refuses to stick to the bed for one of three reasons: the nozzle sits too high above the surface (wrong Z-offset), the plate is contaminated with grease, or the bed temperature is too low for the material. The good news? In 9 out of 10 cases you can fix it in a few minutes without spending a penny. Below you’ll find the 9 most common causes — from the trivial to the easily forgotten — with practical fixes for each.
1. A dirty bed — the invisible enemy number one
Remove one print with bare hands and a thin film of finger grease stays on the plate. PLA and PETG literally slide on it — the first layer looks fine for a moment, then lets go along with the corners.
The fix: wipe the bed with isopropyl alcohol (IPA, at least 90%) before every print. Every 2–4 weeks, wash the plate with warm water and dish soap — soap dissolves grease more effectively than alcohol alone. After washing, keep your fingers off the print surface.
2. A poorly levelled bed
If the filament sticks on one side of the plate and “floats” on the other, levelling is almost certainly to blame. Automatic sensors compensate for minor irregularities, but they don’t replace mechanical levelling — if the bed is badly tilted, no probe can work miracles.
The fix: heat the bed to printing temperature and level it with a sheet of paper at all four corners, and only then run the automatic mesh calibration. Levelling a cold bed is a common mistake — metal expands with heat and the results drift.
3. Wrong Z-offset — nozzle too high or too low
This is the single most common cause of first-layer trouble. If the nozzle is too high, the filament lands on the bed as a round noodle and has no chance to bond. If it’s too low, the nozzle ploughs into the surface and the material has nowhere to flow.
The fix: print a simple test line and look at its cross-section. A properly squished first layer is slightly flattened, matte and has even edges. Adjust the Z-offset in steps of 0.02–0.05 mm — it really is the tiny values that make the difference.
4. Bed temperature too low
Every material has a temperature range where adhesion is best. A bed that’s too cold makes the plastic shrink the moment it touches the plate and lose contact with it.
| Material | Bed temperature | Notes |
|---|---|---|
| PLA | 55–60 °C | usually no glue needed on clean PEI |
| PETG | 70–80 °C | use glue as a separator on smooth PEI |
| ABS | 95–110 °C | an enclosure is a must |
| ASA | 90–100 °C | like ABS, slightly less shrinkage |
| TPU | 30–50 °C | with flexibles, less is more |
You’ll find the full overview for all materials in our temperature table, and detailed PLA settings in our guide to PLA printing temperature.
5. First layer printed too fast
The first layer is not a race. At high speeds the filament has no time to bond with the surface — the nozzle drags it along before it can adhere.
The fix: set the first-layer speed to 20–25 mm/s and its height to about 0.2 mm with a 0.4 mm nozzle. A slightly wider first-layer line (120–140% of the nozzle width) further increases the contact area with the plate.
6. Cooling fan on from the first layer
Part cooling improves bridges and fine details, but on the first layer it works against you: it chills the material rapidly and weakens its bond with the plate.
The fix: set the fan to 0% for the first 2–3 layers. With ABS and ASA, cooling should stay minimal for the whole print.
7. Moist filament
Moisture turns to steam inside the nozzle. The result is hissing, surface bubbles, matte and brittle walls — and noticeably worse first-layer adhesion. PETG, nylon and TPU absorb water especially eagerly.
The fix: dry the filament and store it with a desiccant. We described the whole process step by step in our guide to storing and drying filament.
8. Draughts and a cold environment
An open window, air conditioning or a printer standing in a chilly garage can ruin even a perfectly calibrated print. Cold air accelerates material shrinkage, and from there it’s a short path to lifting corners — we covered this in more depth in our article on warping.
The fix: move the printer away from windows and vents. With ABS and ASA an enclosure isn’t optional — it’s a necessity.
9. A worn or unsuitable build surface
PEI sheets lose their properties over time: scratches, worn spots and areas where nothing wants to stick. Every surface also has its own character — smooth PEI holds PLA brilliantly, textured PEI copes better with PETG.
The fix: a thin layer of glue stick or hairspray helps in the short term; replacing the sheet is the long-term solution. Fun fact: with PETG on smooth PEI, glue also works the other way round — as a separator protecting the plate from a print that bonds too strongly.
Most common mistakes
- Raising the nozzle temperature instead of fixing the Z-offset — more heat masks the symptoms but doesn’t solve the problem, and it makes stringing worse.
- Cleaning PEI with acetone — acetone degrades the PEI coating over time; use IPA for everyday cleaning.
- Touching the plate right after washing it — one second and the grease is back.
- Skipping the brim on models with a small contact area — tall, slim models almost always need a brim or a raft.
- Printing on a cold bed to save time — a few minutes gained, hours lost to a detached print.
Frequently asked questions
What is the best bed temperature for PLA?
PLA works best at 55–60 °C. On a clean PEI plate in this range, PLA holds firmly without glue. If the print still comes loose, the cause is usually not the temperature but the Z-offset or a dirty surface.
Does a glue stick really help?
Yes. A thin layer of glue improves adhesion on glass and smooth PEI, and with PETG it also acts as a separator that protects the plate from a print bonding too strongly.
Why does my print detach only after several layers?
That’s usually not an adhesion problem but material shrinkage. The shrinking upper layers pry up the corners of the print. A brim, a higher bed temperature and shielding the printer from draughts all help.
How often should I clean the printer bed?
With isopropyl alcohol, ideally before every print; every 2–4 weeks it’s worth washing the plate with warm water and dish soap, which removes grease more effectively than IPA alone.
One last thing that’s easy to forget: a consistent, predictable filament means stable flow, and stable flow means a repeatable first layer. If your results are still a lottery despite good calibration, start with a proven material — for example Porima PLA, the filament many of our customers started their frustration-free printing journey with.