Development of the first successful moisture-proof cellophane film is reenacted here at DuPont's Experimental Station near Wilmington, Del. by the inventor, the late Dr. Hale Charch. The new film was developed after 2500 formulas had been tried and hundreds of tests made. Large bag on right held water for weeks, while control bags made3 of untreated film showed evaporation losses in a few days.
