The composition and use of polymeric binders in fabricating parts by selective laser sintering. The binders are amorphous copolymers of methacrylic acid derivatives and may contain styrene and its derivatives, as well as additives, such as film forming agents and adhesion promoters. The binders are used to coat inorganic particulate substrates to create a powder comprised of the substrate and binder. The binders flow to form an interconnecting polymeric matrix upon the application of sufficient energy from the laser beam in a selective laser sintering process. Parts are thus fabricated by directing laser energy onto layers of the powder applied at a target surface (4) in successive fashion to build up a three-dimensional part comprised of a plurality of such layers. The part may then be subjected to a high temperature annealing process in a reducing environment, whereby the binders are virtually completely removed by thermal depolymerization of the copolymer, leaving an insignificantly small amount of residual ash.