Multi-layer fabric

Claim 1

A two layer woven fabric for use in retaining hardenable compositions prior to hardening, said fabric comprising two layers of fabric material in adjacent superimposed relationship, each of said layers including weft threads and ground warp threads woven together, said fabric further including a plurality of interconnecting warp threads, each of said interconnecting warp threads extending back and forth between several successive adjacent weft threads of one layer in loose woven arrangement therewith, for a distance along said fabric and then extending directly to and interweaving with the other layer, the loose woven arrangement of the interconnecting warp threads in said one layer being held between adjacent ones of said several weft threads in the form of several small loops comprised of a predetermined excess length of said warp threads, said two layers being held close to each other by the interconnecting warp threads with the excess length of said interconnecting warp threads being distributed along said fabric in non-entangling configuration, whereby, upon receipt of a hardenable composition between said layers, said interconnecting warp threads are pulled tightly about the several weft threads to permit said predetermined excess length of said interconnecting warp threads to extend between the layers to determine their extent of separation.