A method of making at least one three-dimensional object by additive manufacturing, including: (a) producing, on a carrier platform, by bottom-up stereolithography from a single batch of polymerizable resin, a composite article comprising and produced in the sequence of: (i) an open lattice layer on the carrier platform； then (ii) a frangible layer on the lattice layer； and then (iii) at least one three-dimensional object on the frangible layer； then (b) cleaning the composite article with a wash liquid while on the carrier platform； (c) optionally separating the composite article from the carrier platform； and (d) optionally further curing the composite article； and then (e) separating the at least one three-dimensional object from the lattice layer by cutting or breaking the frangible layer.
