Examples disclosed herein relate to selecting a 3D printing parameter based on voxel property association and conflict resolution. In one implementation, a processor assigns properties to a voxel of a 3D print object based on a first and second zone including the voxel and a condition of a first property associated with the first zone and a condition of a second property associated with the second zone. The processor may update the assigned properties to resolve conflicts between the properties and select a 3D printing parameter based on the assigned properties.