Pair of letter press printing plates

Pair of letter press printing plates from Dumfries and Galloway Standard, 1979.    These printing plates are cast from a lead alloy with an exact inverse copy of the front page of the newspaper from June 2nd 1979, this being the last date of printing at the Standard offices site on the High Street, Dumfries.  The reverse side of the plate has a series of channels built in for location on the printing cylinder.  This type of letterpress printing plate would be used in a 'rotary webfed' type process.   In rotary web fed presses a continuous roll of paper is fed between two cylinders, the plate cylinder and the impression cylinder.  The plate cylinder, either electrotype or stereotype, is automatically inked and pressed against the paper as it unrolls.  After the paper is printed, it can be cut into individual sheets and folded.  Flatbed and rotary presses can be designed to print on both sides of the paper simultaneously and to reproduce colour illustrations.  These machines were responsible for the enormous growth of newspapers during the 19th century.