Method of producing a spirit master from a positive and a duplicating process with same

Claim 1

IN THE METHOD OF PRODUCING COPY FROM A POSITIVE HAVING AN OPAQUE IMAGE ON A LIGHT-TRANSMITTING BACKGROUND, THE STEPS OF EXPOSING TO LIGHT THROUGHT THE POSITIVE, A MASTER SHEET HAVING SUBSTANTIALLY CONTINUOUS COATING CONCENTRATED ON THE SURFACE PORTION THEREOF FORMED OF A COMPOSITION CONTAINING A HIGH PROPORTION OF A SOLUBLE AZO DYE FORMING COMPONENT WHICH IS SENSITIVE TO LIGHT AND WHICH IS SOLUBLE IN THE FLUID APPLIED TO THE SURFACE OF THE COPY SHEETS PRIOR TO CONTACT WITH THE COATED SIDE OF THE MASTER WHEREBY THE AZO DYE FORMING COMPONENT IN THE COATING ON THE MASTER SHEET IS DESTROYED IN THE EXPOSED PORTIONS AND RETAINED IN THE IMAGED PORTIONS TO FORM AN IMAGED PLATE, CONTACTING THE IMAGED SURFACE OF THE MASTER WITH COPY SHEETS WETTED WITH A FLUID CONTAINING A SOLVENT FOR THE AZO DYE FORMING COMPONENT AND THE OTHER COMPONENTS FOR REACTION THEREWITH TO FORM THE AZO DYESTUFF IN THE COPY SHEETS WHEREBY SOME OF THE AZO DYE FORMING COMPONENT IS TRANSFERRED FROM THE IMAGED MASTER TO THE COPY SHEETS UPON CONTACT WHERE REACTION TAKES PLACE TO FORM THE AZO DYESTUFF.