Generally, the older nonmetallic composite systems have employed shorter length fibers, while in the newer generation of composites the reinforcement runs the entire length of the particular specimen, or along the entire respective axes of angle-ply reinforced composites. This chapter provides a more extended coverage both to specific matrices, which have been employed with the new continuous filaments such as boron, and the reinforced composite structures. Consideration of angle-ply composites which are becoming increasingly important has also been given. The chapter tabulates different material properties of different epoxy resin matrices such as Narmco 5504, boron unidirectional composites such as Bp 907, graphite unidirectional composites such as Erla-2256, boron angle-ply composites such as BP 907, and graphite – composites such as Erla-2256.