Heat-sensitive copying method for preparation of printing stencils

摘要

A stencil sheet having a thin stretched thermoplastic resin film supported on an ink pervious porous substrate is positioned on an original manuscript in a manner such that the film may be in close contact with the imaged side of the manuscript. The assembly is then irradiated by a light which is rich in rays having a wavelength ranging from 0.7 to 1.2 microns and has a flash duration of from 10-4 to 10-3 second. A xenon-filled electronic flash discharge tube is found to be the most suitable light source. Stencil openings formed thereby on the film surface are excellent in definition and free from marginal swelling therearound. The stencil prepared by this method can produce copies of 2000 or more which correspond exactly with the original manuscript.