3D (three-dimensional) ink jet printing includes techniques for evaporating a carrier liquid during printing while at least a portion of dispersant remains in the printed layer; evaporating dispersant in a first layer prior to sintering the first layer and/or prior to printing a second layer; leveling an upper-layer of a printed object using a horizontal roller; and printing layers of an object, each layer with both object and support portions, resulting in an object with support, in particular, support for negative angles and molds.