Abstract: An acoustical and thermally absorbent composite formed of thermoplastic bonding materials and reinforcing fibers is provided. The reinforcing fibers are preferably wet use chopped strand glass fibers (WUCS). The thermoplastic bonding materials may be any thermoplastic or thermosetting material having a melting point less than the reinforcing fiber. The composite material may be formed by partially opening the WUCS fibers and bonding fibers, blending the reinforcement and bonding fibers, forming the reinforcement and bonding fibers into a sheet, and bonding the sheet. The composite material is a lofted insulation product that may be used as a reinforcement backing for cladding such as vinyl siding. The composite material may be affixed to the siding by ultrasonic welding. After the composite material has been affixed to the siding, the siding product may be vacuum packaged within an air-impervious material to reduce the storage and/or shipping space required for the siding product.