Processing build materials

A build material processing system comprising:

• a build volume interface to receive a container including a build volume comprising a plurality of powdered build material layers in which an agent has been selectively applied to define a 3D object;
• at least one type of build material removing device;
• a controller to:
• control the build material removing device to extract a first portion of the powdered build material layers in a first manner;
• control the build material removing device to subsequently extract a second portion of the powdered build material layers in a second manner;
• and
• convey the extracted second portion of the powdered build material layers to a reconditioning unit;
• and
• a sensing module to determine a quality level of the second portion of the powdered build material layers,
• wherein the controller controls the reconditioning unit to treat the second portion of the powdered build material layers based on the determined quality level.