Composite sheets include at least two adjacent fibrous monolayers of unidirectionally aligned high tenacity polyethylene fibers, whereby the direction of orientation between the polyethylene fibers of said two fibrous layers differs by at least 80° and up to 90°, the fibers having a tenacity of at least 1.5 N/tex, the fibers being in a matrix comprising a homopolymer or copolymer of ethylene and wherein the homopolymer or copolymer of ethylene has a density as measured according to ISO1183 of between 870 to 980 kg/m3. The composite sheets have an areal density of between 50 and 500 g/m2, wherein the composite sheets have an areal density normalized in-plane shear force measured at 25° C. evaluated according to a bias extension test method variant of ASTM D3518 of at least 0.40 N·m2·g−1 and lower than 5.0 N·m2·g−1 at 10 mm clamp displacement and an areal density normalized in-plane shear force measured at 110° C. and clamp displacement of 10 mm of at least 0.01 N·m2·g−1 and lower than 0.20 N·m2·g−1.