Ultra-high molecular weight polyethylene (UHMWPE) is commonly utilized for ballistic protection due to its high strength to weight ratio. Commercially available UHMWPE sheet-stock is comprised of aligned fibers or films embedded in a thermoplastic polymer matrix. Fiber based UHMWPE sheet-stock typically consists of four layers of unidirectional material, with two oriented in the roll direction and two perpendicular. Literature shows that performance of UHMWPE is highly dependent on processing pressure, making the understanding of pressure distribution during high pressure, high temperature consolidation critical for ensuring parts have uniform mechanical properties. This work presents a methodology for quantifying pressure distributions in-situ during the processing of UHMWPE composites at elevated temperatures. Pressure gradients are quantified for uniform parts with common boundary conditions. Compound curvature parts have been demonstrated to have non-uniform thicknesses due to shear induced thickening in some regions. The dependence of pressure on part thickness uniformity will be experimentally studied to develop a relationship between thickness gradients and pressure distributions. A finite element model will be presented and used to demonstrate the effect of thickness gradients on pressure distributions in complex compound curvature parts, which has yet to be experimentally measured.