Computer programs were developed to produce graphic plots which simulate the lowangle x-ray scattering curves obtained from cast films of triblock copolymers. Models were developed to take account of lattice paracrystallinity, a distribution in size of the scattering elements, various types of lattice packing, and the possibility of more than one type of lattice packing in a loosely bound paracrystal. These studies provide an insight into the possible structure of the macrolattices which have been observed with triblock copolymers.