Print quality issues

Poor build plate adhesion

When you experience problems with the adhesion of a print to the build plate, the following actions can be performed:

  • Ensure that the correct material settings and adhesion methods were used (see the "Operation" tab to the right).
  • Recalibrate the build plate manually and then do the active leveling (see the "Maintenance" tab to the right).
  • Check the Ultimaker Cura settings that were used, and try printing with one of the default Ultimaker Cura profiles.

Learn about build plate adhesion.

Grinding PVA

Typically, incorrect handling or storage of the material can lead to grinding. PVA should be printed and stored at a low humidity to avoid problems while printing. We advise a humidity below 50% for storage and below 55% while printing. It is also recommended to keep the ambient temperature below 28 °C while printing. In a standard air-conditioned office, this humidity and temperature should be easy to achieve.

When PVA is ground down by the feeder, there are three main causes:

Incorrect storage

PVA is a material that absorbs moisture relatively easily, and therefore storing it correctly (in a resealable bag, with humidity below 50%) is important. If PVA absorbs too much moisture it will get soft and malleable/pliable and in some cases even sticky. This can cause problems in the feeder as it might not be able to forward the PVA properly anymore.

Coated Bowden tube

The Bowden tube can get coated on the inside due to incorrect printing conditions (mainly high humidity). If the humidity of the printing environment is too high (above 55%) and temperature is too high (above 28 °C) PVA might not be able to move easily through the Bowden tube. A solution for this is to clean the Bowden tube and dry it very well.

Clogged print core

High humidity can affect PVA quality, and lead to clogs in the print core. As a consequence, filament might get jammed, causing grinding in the feeder. When this happens, the print core should be cleaned by following the procedure described here.


In its simplest form, under-extrusion is when the printer is unable to supply the right amount of material. Your Ultimaker 3 is under extruding when you see missing layers, very thin layers, or layers that have random dots and holes in them.

Under-extrusion can have several causes:

  • Use of low-quality material or wrong material settings
  • Feeder tension not set correctly
  • Friction in the Bowden tube
  • Small particles of material in the feeder or Bowden tube
  • A partial clog in the print core

This Ultimaker Robot shows signs of under-extrusion.

Learn how to troubleshoot under-extrusion.


Warping occurs due to material shrinkage while 3D printing, which causes the corners of the print to lift and detach from the build plate. When plastics are printed, they firstly expand slightly but contract as they cool down. If material contracts too much, this causes the print to bend upwards from the build plate.

When your print is warping, make sure you have done the following:

  • Level the build plate correctly (preferably active leveling)
  • Apply a thin layer of glue to the glass plate
  • Use the correct temperature settings
  • Use one of the default Cura profiles

This print shows signs of warping.

Learn how to fix warping.