Oriented strand board (OSB), also known as sterling board, sterling OSB, aspenite, and smartply in British English, is an engineered wood particle board formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations.t was invented by Armin Elmendorf, California US in 1963 OSB Patent. OSB may have a rough and variegated surface with the individual strips of around 2.5 × 15 cm (1 × 6), lying unevenly across each other and comes in a variety of types and thicknesses.