a self supporting curved laminate product resulting from curving of a planar precursor , wherein the planar precursor is a self supporting laminate of two sheets of an acrylic thermoplastic , or of sheets including an acrylic thermoplastic , spaced by , but attaching to , an interposed thermoset polyester system , and wherein curving has involved heating of the laminate sufficient to allow its curving without any substantial degradation of the lamination or its component layers .