AbstractExperiments utilizing charges constructed of black and white sheet molding compound (SMC) reveal the basic kinematic mechanisms controlling the flow of the fiber‐filled compound in compression molding. The experimental results show that SMC deforms in uniform extension within individual charge layers, with slip occurring at the mold surface and, for slower closing speeds, also between the layers of SMC. When the mold closes rapidly, the charge extends uniformly through its thickness, with all slip concentrated at the mold surface.