Material for reinforcing duroplastics woven fabric for reinforcing duroplastics having a specific distribution of hollow thermoplastic microspheres within the thread system

In a reinforcing material for duroplastics comprising a woven web, having at least two interwoven thread systems and hollow thermoplastic microspheres with a diameter of 20 to 300 .mu.m positioned inside the thread systems, the improvement wherein the woven web has a floating weave, of warp and weft threads wherein each warp thread skips two weft threads so that particular points (a) of intersection of one pair of warp threads are displaced one weft thread from points (a) of intersection of an adjacent pair of warp threads, the thread system extending in the warp direction containing approximately 60 to 100% by volume of the microspheres and covering at least partly the thread system extending in the weft direction containing 40 to 0% by volume of the microspheres, the reinforcing material having an almost flat and board-like surface.