Layers splitting or cracking

Layers come apart along a line, or cracks open up in the walls, especially on tall prints.

Also described as delamination, layers splitting, cracks, layer separation, weak layers, splitting apart, cracking

Try these in order

Most likely and quickest to check first. Change one thing at a time so you know what fixed it.

Too cold
Each layer has to melt into the one below. Too cold and they barely stick.
- Raise the nozzle temperature by 5 to 10 °C, or print a temperature tower and check the strength of each band.
Temperature tower
Too much cooling or draughts
- Lower the fan speed for PETG, ABS and ASA.
- Use an enclosure for ABS, ASA, nylon and PC.
Which materials need an enclosure
Under-extrusion
- Check for a partial clog, and calibrate the flow rate.
Wet filament
- Dry the spool.
Drying times