Most stereolithography systems use a blade to accomplish the recoating of the part being built with a new layer of resin. States the problems associated with this technique and describes experiments conducted to determine how recoating parameters should be controlled. Differentiates between recoating over an entirely solid substrate and over one consisting of solid and liquid, i.e. the trapped volume condition. Discusses parameter control for both of these conditions. Concludes that recoating is an important part of the stereolithography process which must be optimized to ensure accuracy of prototype parts.