This material is a solution of polymethyl methacrylate in styrene, which is used as an additive to reduce shrinkage and shrinkage of composite parts produced by BMC and SMC methods, especially in the production of automobile parts. Unsaturated polyester resin shrinks by 7 to 9% by volume during baking. Therefore, molding by SMC and BMC methods causes the formation of an uneven, wrinkled and cracked surface, which can be easily solved by adding BM852 resin. is solved