Examples of the present disclosure relate to a method for packing three dimensional (3D) models. The method comprises identifying a plurality of sections of each 3D model according to curvature profiles of the sections; associating a build material layer thickness to each section of the plurality of sections, whereby each associated build material layer thickness is one of a set of pre-established build material layer thicknesses; packing the plurality of 3D models according to each associated build material layer thickness, whereby packing comprises spatially arranging at least some 3D models in the 3D virtual build volume according to one or more criteria, such that at least some of the sections of different 3D models associated to a same build material layer thickness are arranged in a same region of the 3D virtual build volume.