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The first layer will not stick to the bed

Severity: HighAffects: Filament (FDM)Updated July 27, 2026

Symptom

Filament comes out of the nozzle but does not stay down: it turns into spaghetti, drags behind the head, or leaves separated rounded lines that peel off on their own. In the worst case the print never gets going.

Likely causes

In order: the most frequent cause comes first.

  1. 01Z-offset too high: the nozzle does not squash the line against the bed
  2. 02A surface dirty with grease, dust or leftovers from a previous material
  3. 03A badly levelled or warped bed with one area lower than the rest
  4. 04Bed or nozzle temperature below what the material asks for
  5. 05First-layer speed too high, or cooling switched on from layer one

How to fix it

Apply one fix at a time and reprint the same test part. Changing three settings at once tells you nothing about which one worked.

  1. 01

    Tune the Z-offset while watching the first layer

    Easy

    Start a print and stay for the first minute. The lines should look slightly squashed and touching each other, with no gaps. If they are rounded and separated, lower the Z-offset in 0.02 mm steps; if they look translucent with burrs at the sides, raise it. Almost every printer lets you adjust it live during the first layer.

  2. 02

    Wash the sheet with hot water and dish soap

    Easy

    It is the cheapest fix and the one that works most often. Isopropyl alcohol removes dust but not grease; dish soap does. Afterwards, do not touch the surface with your fingers again.

  3. 03

    Slow down and turn off the fan on the first layer

    Easy

    In the slicer, set first-layer speed to around 20 mm/s and part cooling to 0 % for that first layer. Giving the material time to settle and not chilling it abruptly solves many borderline cases without touching anything else.

  4. 04

    Re-run auto-levelling and inspect the sheet

    Medium

    If the problem appears only in one area of the bed, re-run levelling with the bed hot and the nozzle clean. A well-worn PEI sheet loses grip and is worth flipping or replacing; a dented one has to be replaced.

How to prevent it

  • —Always watch the first minute of every print before walking away
  • —Wash the sheet with soap regularly and handle it by the edges
  • —Write down your Z-offset for each sheet and material combination
  • —Wipe the nozzle while hot before printing if the previous job left residue

Sources

  1. [1]First layer issues | Prusa Knowledge BasePrusa Research · Manufacturer · accessed July 27, 2026

Related problems

HighFDM

Warping: the part lifts and its corners curl up

The part's corners and edges separate from the bed mid-print and end up curled upward. The base stops being flat and, if the lifting continues, the head eventually knocks the part loose.

HighFDM

Under-extrusion: less material comes out than it should

Material lines are missing within layers: gaps appear between beads, walls look thin and translucent, and the part breaks easily. Prusa describes it as layers missing material and fragile parts that tend to fall apart.

LowFDM

Elephant foot: the base comes out flared

The first layers protrude beyond the rest of the part, forming a lip around the base. The part does not sit flat, will not slot into its housing, and its lower dimensions are larger than designed.