First Layer Not Sticking to the Build Plate
Fix prints that peel away, fail to attach, or turn into loose strands during the first layer.
A reliable first layer is the foundation of a successful 3D print. If the filament does not stick properly, the print may detach completely or get dragged around by the nozzle.
Start by cleaning the build plate. Fingerprints, grease and dust can dramatically reduce adhesion. Wash removable build plates with warm water and a small amount of dish soap, then dry thoroughly. Avoid touching the printing area afterwards.
Next, check your nozzle height or Z-offset. If the nozzle is too high, the filament will look round rather than being gently squashed against the plate. If it is too low, filament may barely come out and the nozzle may scrape the surface.
Run your printer's automatic bed levelling routine if available.
Check that the correct build plate is selected in your slicer and that your first-layer temperature matches the filament being used.
For PLA, a bed temperature around 50–65°C is a common starting point. PETG generally benefits from a warmer bed.
Try slowing the first layer to around 15–30 mm/s.
A good first layer should consist of lines that touch each other without deep ridges or gaps.
If adhesion is only poor in one part of the bed, bed levelling, a warped plate, or contamination in that area is more likely than a filament problem.
Common causes: dirty build plate, incorrect Z-offset, poor bed levelling, incorrect temperature, excessive first-layer speed.