Introduction
A first layer that peels, warps or simply slides across the build plate is the number-one reason people give up on 3D printing within the first week. The good news is that bed adhesion failures are rarely caused by a faulty printer. In almost every case, the problem comes down to incorrect levelling, a dirty build surface, wrong temperatures or slicer settings that haven’t been tuned for the filament you’re using. This guide walks through each cause in order, from the quickest fix to the most involved, so you can get a reliable first layer on every print.
Why This Happens
The first layer of any FDM (Fused Deposition Modelling) print is the foundation for everything above it. The nozzle extrudes molten plastic onto the build plate, and that plastic needs to be pressed firmly enough to create a mechanical bond with the surface. If the nozzle is too far away, the filament lands as a loose thread and doesn’t grip. If the bed surface has oils, dust or residue from a previous print, the plastic can’t make full contact. If the temperature is too low, the filament cools and contracts before it has time to bond.
Different filaments behave differently. PLA is the most forgiving and sticks well to clean PEI, glass and textured build plates at moderate temperatures. PETG bonds aggressively to smooth PEI — sometimes too well — and needs a slightly higher bed temperature. ABS and ASA are the most prone to lifting because they shrink significantly as they cool, pulling the corners upward. The build surface material also matters: a textured PEI spring steel sheet grips better than smooth PEI for most materials, whilst glass beds work well when paired with a thin layer of PVA glue stick.
Printers with automatic bed levelling (ABL) sensors like the BLTouch, CR Touch or inductive probes reduce manual effort, but they don’t eliminate the problem entirely. The probe measures the bed shape and compensates during printing, but it doesn’t set the Z offset — the gap between the nozzle tip and the bed surface. If the Z offset is wrong, even a perfectly levelled bed will produce poor adhesion.
Step-by-Step Fix
1. Clean the Build Surface
Before adjusting anything mechanical, wipe the entire build plate with isopropyl alcohol (IPA) at 90% concentration or higher. Use a lint-free cloth or paper towel. Finger oils from handling the plate are invisible but enough to prevent adhesion. Do this before every print — it takes ten seconds and solves the problem roughly a third of the time on its own.
If IPA alone doesn’t help and you’re using a PEI sheet, wash it with warm water and a small drop of washing-up liquid once a week. Rinse thoroughly and dry completely before reinstalling.
2. Level the Bed (Manual Printers)
If your printer uses manual bed levelling (four corner adjustment wheels), follow this process:
- Home the printer using the control panel or display menu.
- Disable the stepper motors (usually under Motion > Disable Steppers on Marlin-based printers).
- Move the print head to each corner of the bed manually.
- Place a sheet of standard 80gsm printer paper between the nozzle and the bed.
- Adjust the corner wheel until the paper slides with slight resistance — you should feel a light drag but still be able to pull the paper out.
- Repeat for all four corners, then go back to the first corner and check again. Adjusting one corner affects the others, so two full passes are normal.
3. Set the Z Offset (Auto-Levelling Printers)
If your printer has a probe (BLTouch, CR Touch, inductive sensor, or Bambu Lab’s built-in lidar), the bed levelling mesh is usually accurate. The issue is almost always the Z offset value.
- Run the auto-levelling routine from the printer menu.
- Start a small test print — a single-layer square or the first-layer calibration model from your printer manufacturer.
- Watch the first layer go down. If the lines don’t touch each other and look rounded on top, the nozzle is too high — decrease the Z offset by 0.02 mm at a time using the live-adjust option during printing.
- If the first layer looks transparent, overly flat, or the nozzle scrapes the bed, the nozzle is too low — increase the Z offset by 0.02 mm.
- The target is lines that are slightly squished together with no gaps between them, and a smooth top surface.
4. Adjust First-Layer Temperature
Open your slicer (Cura, PrusaSlicer, Bambu Studio, or OrcaSlicer) and check the first-layer temperatures:
- PLA: Nozzle 210–215°C, Bed 60–65°C for the first layer
- PETG: Nozzle 235–240°C, Bed 80–85°C for the first layer
- ABS/ASA: Nozzle 245–250°C, Bed 100–110°C for the first layer
Setting the bed temperature 5–10°C higher for the first layer than for subsequent layers improves adhesion without causing other issues. Most slicers have a separate “initial layer temperature” setting.
5. Slow the First-Layer Speed
In your slicer, find the first-layer speed setting and reduce it to 20–25 mm/s. This gives the filament more time to melt onto the surface and form a proper bond. The default first-layer speed on many printers is 30–50 mm/s, which is too fast for tricky filaments or worn build surfaces.
6. Add a Brim or Raft (If Needed)
If the print still lifts at the corners — especially with tall, narrow models — add a brim in your slicer. A brim prints extra lines around the base of the model, increasing the surface area touching the bed. A 5 mm brim is usually enough. Avoid rafts unless you’re printing ABS or a material that genuinely needs one, as rafts waste material and leave a rough bottom surface.
Common Mistakes to Avoid
Using glue stick or hairspray as a first resort. Adhesion aids mask the real problem. If you need glue on a PEI sheet, your Z offset or temperatures are wrong. Fix those first — adhesion aids should be a last resort, not a daily habit.
Levelling the bed once and never checking again. Bed springs compress over time, and thermal cycling shifts the adjustment. Check the level every 10–15 prints, or whenever you notice first-layer inconsistency. Upgrading to silicone spacers instead of springs reduces drift significantly.
Setting the nozzle too close to the bed. Over-squishing the first layer looks like good adhesion, but it causes elephant’s foot (a flared base) on every print and can damage the build surface or nozzle. If the first layer looks glassy or transparent, you’ve gone too far — back off by 0.02–0.05 mm.
Ignoring ambient temperature. If your printer is in a cold garage, conservatory, or near an open window, draughts cool the print unevenly and cause warping that no amount of bed temperature will fix. Either move the printer to a stable indoor environment or use an enclosure.
Printing on a dirty or worn build surface without realising it. PEI sheets lose their grip after hundreds of prints. If cleaning with IPA and washing-up liquid no longer helps, lightly scuff the surface with 1000-grit sandpaper or replace the sheet. A textured PEI sheet typically lasts longer than a smooth one.
When to Call a Professional
If you’ve worked through every step above and the first layer still won’t stick, the problem may be mechanical. A warped aluminium bed that the auto-levelling sensor can’t fully compensate for, a partially blocked nozzle that causes inconsistent extrusion, or a faulty thermistor that reports the wrong bed temperature can all mimic simple adhesion failures. On kit-built printers, frame misalignment or loose eccentric nuts on the gantry wheels can also prevent the nozzle from maintaining a consistent height across the bed.
These faults are difficult to diagnose without experience — you can spend hours adjusting settings that will never fix a hardware misalignment. If you’re in South West London, our 3D Printer Setup & Calibration service includes a full mechanical check, bed levelling, Z offset calibration, and a test print to confirm everything is working. We work with Creality, Prusa, Bambu Lab, Anycubic, Elegoo and most other consumer FDM printers.
Prevention Tips
Clean the build plate with IPA before every print. This single habit prevents more adhesion failures than any other adjustment. Keep a spray bottle of 99% IPA and a roll of paper towel next to the printer.
Use a textured PEI spring steel sheet for PLA and PETG. Textured PEI provides excellent grip without adhesion aids, releases prints easily once the plate cools, and is more durable than smooth PEI. Most printer manufacturers sell them as accessories.
Store filament in a dry box or sealed bag with desiccant. Wet filament (especially PETG and Nylon) produces steam bubbles during extrusion that weaken the first layer bond. If your filament has been sitting open for more than a week in a humid room, dry it in a filament dryer at 50°C for 4–6 hours before printing.
Print a first-layer calibration test after any hardware change. Swapping nozzles, changing build plates, or updating firmware can shift the Z offset. A quick single-layer test square takes two minutes and catches problems before they ruin a long print.
Keep the printer on a stable, level surface away from draughts. Vibration from an unsteady desk causes layer inconsistencies, and air currents from windows or doors cool the print unevenly, both of which make adhesion worse.