Printing plate construction

Claim 1

A PROCESS OF PRODUCING A ROTOGRAVURE PRINTING CYLINDER SURFACE COMPRISING THE STEPS OF MAKAING A CONTINUOUS TONE COLOR SEPARATION NEGATIVE FROM THE COPY IN WHICH THE DENSITY IN THE HIGHLIGHTS IS ABOUT 1.70 AND IN THE SHADOWS ABOUT 0.30, RETOUCHING THE CONTINUOUS TONE NEGATIVE, EXPOSING THE CONTINUOUS TONE NEGATIVE THROUGH A HALF-TONE SCREEN HAVING UNIFROM SQUARE APERTURES WHOSE SIDES ARE AT AN ANGLE OF 45* FROM THE SIDES OF A STANDARD ENGRAVER''S SCREEN, THE RATIO OF THE SCREEN AS TO TRANSPARENCYY AND OPACITY BEING ABOUT 40 TO 60, THE SCREEN SEPARATION BEING ABOUT 40-THOUSANDTHS OF AN INCH FROM THE SURFACEE OF THE SCREEN STRUCTURE TO THE EMULSIOSN SIDE OF THE PHOTOGRAPHIC PLATE, NO COVER GLASS BEING USED ON THE SCREEN THEREBY OBTAINING A HALF-TONE JPOSITIVE WITH SQUARE OPAQUE DOTS IN THE SHADOWS AND ROUNDS OPAQUE DOTS IN THE 20% TONE VALUES AND IN THE HIGHLIGHTS, THE DOTS IN THE SHADOWS BEING IN THE RATIO OF OPACITY TO TRANPARENCY OF ABOUT 4 TO 1, DOT ETCHING THE HALF-TONE POSITIVE FOR COLOR COR-