Composite products incorporating a polymer matrix, polymer microspheres, glass microspheres and natural fibers, particularly kenaf are described. The polymer microspheres are 15 to 50 microns in diameter and are smaller that the glass microspheres which are 50 to 200 microns in diameter. The polymer microspheres reduce voids and prevent cracking of the glass microspheres upon compression. The composites have low cost and high strength.