Plastic materials in the form of sheets and blocks, namely, plastic sheets for use in the manufacture of displays and signs, extruded plastics materials in the form of blocks and sheets for use in manufacture, plastic sign blanks, semi-processed plastic materials in the form of blocks and sheets; semi-processed plastic in the form of sheets for arts and crafts; plastic substrates, namely, plastic and corrugated PVC fluted substrates and plastic and corrugated PVC fluted substrates for use in ...