The production process of the epoxy/BNNS/BNNT composites is illustrated in Figure . The composites were created by blending and curing the fillers (BNNS and BNNT powders) with epoxy with loadings ranging from 0 wt% to 30 wt% for BNNS and 0 wt% to 2 wt% for BNNT using a Speed Mixer DAC 600.2 VAC-P under vacuum. The mixture was then poured into a silicone rubber mold and left to cure overnight at room temperature. The composite samples were then hot pressed at a pressure of 10 tonnes and a temperature of 60C followed by a curing cycle of 80C for 1 hour and 140C for 8 hours. After curing, the samples were removed from the mold and polished to remove any marks and surface voids. It was observed that the viscosity of the epoxy-BN mixture increases significantly with increasing BN content and became a very stiff paste at high BN content. This effect is particularly pronounced for the smallest BN particles (5 µm), for which the 40% BN content could not be achieved because the surface area to volume ratio increases as the particle size decreases.