Heath v. Frankel

GARRECHT, Circuit Judge.-

The two Heath patents in suit were issued to appellant to cover the use of cellophane and pliofilm as protective sheets for stencils. Before cellophane was used as a protective sheet, mere outlines were all that could be made on duplicating stencils with the stylus by anyone other than an expert without weakening the structure of the stencil. Without cellophane, the stylus picked up the minute fibers and destroyed the stencil structure, so that when the stencil was placed on the duplicating machine, the longitudinal pull on the stencil broke down the stencil fibers…