SlicerDial

First layer not sticking: Z offset, a clean plate and the right surface

Published October 15, 202614 sources

Short answer

Most first-layer failures trace to a dirty plate, a nozzle set too high, or a plate and slicer setting that do not match the filament [11, 1]. Clean the plate as its maker specifies, recheck leveling and Z offset, confirm the plate type in the slicer, then try a bed 5–10 °C hotter and a slower first layer [1]. On smooth PEI, Bambu Lab requires glue for every filament except PLA, and Prusa recommends a separation layer for PETG [9, 2].

Symptom, likely cause, what to check

Bambu Lab names skin oil on the plate as the most common cause of prints coming loose, followed by the wrong plate type in the slicer and a nozzle that sits too high on the first layer [11]. Prusa calls first-layer trouble by far the most common 3D printing problem and lists the same culprits plus speed, temperature and sheet placement [1].

Symptom Likely cause What to check
Round, unsquished lines that peel up Nozzle too high Z offset or Live Adjust Z [5]
Little or no plastic for the first layer or two Nozzle too close to the bed Raise the Z offset [1]
Poor patches in the first layer that match fingerprints Skin oil on the plate Wash or degrease the plate [7]
Water beads into droplets on a textured PEI plate Contaminated surface Wash with detergent until water forms a thin film [7]
Adhesion dropped after swapping plates on a Bambu Lab printer Wrong plate type in the slicer Plate type setting [6]
Small or tall, thin parts get knocked loose Small contact area Brim, or supports for tall parts [7]
Smooth PEI tore when a PETG part came off Bond too strong, no separation layer Glue stick or another plate [2]
Smooth PEI grips less over time despite cleaning PEI can lose adhesion after a couple of hundred hours Occasional acetone wipe, smooth PEI only [1]

Diagnostic order

  1. Clean the plate using the method its maker specifies (next section).
  2. Seat the sheet. Check that nothing, such as a stray strand of filament, sits under the sheet, and that the sheet is flat and undamaged [1].
  3. Select the right plate in the slicer. Bambu Lab printers lower the nozzle 0.04 mm after leveling on the Textured PEI Plate, and bed temperatures differ by plate, so a mismatch can leave the first layer too high or the bed too cool [6].
  4. Level and set Z offset. Bambu Lab recommends running bed leveling calibration with a clean nozzle tip and leaving the per-print leveling option on [6]. On Prusa printers with a PINDA probe, First Layer Calibration and Live Adjust Z set the height; LoadCell models such as the MK4/S and CORE One calibrate automatically, and PrusaSlicer’s Z offset fine-tunes it, with negative values squishing more [5]. On Klipper, PROBE_CALIBRATE with a paper test measures the probe z_offset [14]. See first layer and Z offset and bed mesh leveling.
  5. Raise the bed temperature. Prusa suggests 5–10 °C more for materials that do not adhere well [1]. Bambu Lab cautions that too hot a bed with PLA or PETG can cause clogging and elephant’s foot [7].
  6. Slow the first layer. Prusa suggests about 75% speed for the first three layers [1]. In OrcaSlicer, Initial layer speed and Number of slow layers control this [13]. Bambu Lab suggests a 0.5 mm first-layer line width and 0.25 mm first-layer height if problems persist [7], and no part cooling for the first 3 layers [11].
  7. Add a brim for small footprints before reaching for adhesives [1].

Prusa warns against fixing poor adhesion by lowering Live Adjust Z too far: the nozzle can damage the sheet and cause excessive vibration [1].

Cleaning: IPA or dish soap depends on the plate

The two makers give different instructions, so follow the one for your plate.

Prusa degreases smooth, satin and textured sheets with 90% or stronger isopropyl alcohol, wiped on the cold sheet with an unscented paper towel; lower concentrations and skin-care products can leave oils. If adhesion still fades, it allows an occasional wash with dish soap and warm (not hot) water to remove residue that IPA misses. Acetone is for the smooth PEI sheet only, about once a month, and never for textured or satin sheets [1].

Bambu Lab washes its Textured PEI Plate with dish detergent and a sponge or plastic brush, then rinses and dries it, because alcohol can spread oils across a textured surface instead of lifting them. The detergent must be free of oils and moisturizers, and acetone damages the plate. A quick check: on a clean plate, water spreads into a thin film instead of beading [7]. Its filament guide recommends regular cleaning with dish soap and hot water for all plates [10].

Both agree on one point: after cleaning, keep fingers off the print surface [1, 7].

When the surface itself is worn

Prusa restores a dull or marked sheet by rubbing it gently with the hard side of a dry kitchen sponge or 400–600 grit sandpaper, then wiping with IPA [1]; for a smooth PEI sheet after one to two years of use it suggests 600–1000 grit [3]. Bambu Lab says fine sandpaper or steel wool can expose a fresh textured PEI surface, provided all sanding debris is cleaned off [7]. If one side of a double-sided plate still will not hold prints, Bambu Lab suggests printing on the other side [8].

Matching the plate to the filament

Plate What the maker says
Prusa smooth PEI Good for PLA, ABS/ASA and composites; PETG, ASA, ABS and PC Blend may need a thin glue-stick layer [3]. PETG can bond hard enough to peel the PEI [2]
Prusa textured (powder-coated) Suited to PETG and TPU; glue stick required for ASA, ABS, nylon and PC Blend; small PLA prints may need a brim [4]
Bambu Lab Smooth PEI Glue is required for every filament except PLA, to avoid damaging the plate when removing parts [9]
Bambu Lab Textured PEI Glue is generally unnecessary; it can make PETG easier to release [9]
Bambu Lab Engineering Plate Glue recommended before printing any filament [9]

Bambu Lab’s filament guide lists bed temperatures per plate. For PLA on the Textured PEI Plate it gives 45–65 °C [10], while its warping guide targets 55–65 °C when corners lift [11]. Brand data-sheet ranges are compared in the temperature chart, and PETG-specific advice is in the PETG guide.

Questions

Do I need glue stick on a textured PEI sheet?

Prusa says its textured sheet needs glue stick as a separation layer for ASA, ABS, nylon and PC Blend but not for TPU [4]. Bambu Lab says glue is generally unnecessary on its Textured PEI Plate but can make strongly bonding filaments such as PETG easier to remove [9].

Why did adhesion drop after I switched plates on a Bambu Lab printer?

Bed temperature depends on the plate type chosen in the slicer, and the printer lowers the nozzle 0.04 mm only when the Textured PEI Plate is selected, so a mismatch leaves the bed too cool or the first layer too high [6].

When should I take the print off the plate?

Both makers say to wait until the plate has cooled. Prusa notes prints then release by flexing the sheet [2], and Bambu Lab adds that waiting until the bed and print reach room temperature avoids burns and plate damage [12].

Sources

  1. First layer issues. Prusa Knowledge Base. Manufacturer documentation. IPA, dish soap and acetone cleaning; glue; Live Adjust Z; 75% speed; +5–10 °C bed. Accessed October 12, 2026.
  2. Print surface preparation. Prusa Knowledge Base. Manufacturer documentation. PETG damage to smooth PEI; separation layers; material table symbols. Accessed October 12, 2026.
  3. Smooth Steel Sheet. Prusa Knowledge Base. Manufacturer documentation. Materials needing glue stick on smooth PEI; maintenance. Accessed October 12, 2026.
  4. Textured steel sheet. Prusa Knowledge Base. Manufacturer documentation. Glue requirements and care for the powder-coated sheet. Accessed October 12, 2026.
  5. Live adjust Z. Prusa Knowledge Base. Manufacturer documentation. Too high vs too close; LoadCell printers; PrusaSlicer Z offset. Accessed October 12, 2026.
  6. First Layer Not Sticking: Causes and Solutions. Bambu Lab Wiki. Manufacturer documentation. Plate type selection, washing, bed leveling calibration. Accessed October 12, 2026.
  7. Bambu Lab Textured PEI Plate Cleaning Guide. Bambu Lab Wiki. Manufacturer documentation. Detergent washing, water-film test, no acetone, first-layer line width and height. Accessed October 12, 2026.
  8. Bambu Lab Textured PEI Plate Troubleshooting Guide. Bambu Lab Wiki. Manufacturer documentation. Coating wear; try the other side of the plate. Accessed October 12, 2026.
  9. How to Use Bambu Lab Glue. Bambu Lab Wiki. Manufacturer documentation. Glue rules per plate: Smooth PEI, Textured PEI, Engineering Plate. Accessed October 12, 2026.
  10. Filament guide: printer, nozzle, AMS, build plate, glue compatibility and required parameters. Bambu Lab Wiki. Manufacturer documentation. Bed temperature by plate and filament; cleaning with dish soap and hot water. Accessed October 12, 2026.
  11. Model Warping, Falling Off, or Collapsing. Bambu Lab Wiki. Manufacturer documentation. Causes of adhesion failure; PLA target on Textured PEI; first-layer cooling. Accessed October 12, 2026.
  12. Work After Printing Finished. Bambu Lab Wiki. Manufacturer documentation. Wait for the plate to cool before removing prints. Accessed October 12, 2026.
  13. Initial layer speed. OrcaSlicer Wiki. Slicer documentation. Initial layer speed settings and number of slow layers. Accessed October 12, 2026.
  14. Probe calibration. Klipper documentation. Firmware documentation. PROBE_CALIBRATE and the probe z_offset. Accessed October 12, 2026.