Reaction injection molding has been tailored to the automotive industry for years. As a result, available resin formulations, processing equipment, and tooling have been optimized for the mass production of large, often structurally reinforced parts and not for relatively small, intricate parts typical of consumer electronic device applications. Industry-wide product development cycle time reduction initiatives require rapidly fabricated prototypes for conceptual and functional design verification. High quality, multifunctional, thin-walled (0.015 to 0.080) plastic parts can be produced within one week after the creation of corresponding 3D CAD models by integrating reaction injection molding (RIM) principles, rubber tooling and rapid prototyping technologies.