Improved Process or Combination of Processes for Improving the Appearance of Engravings and the like

摘要

14,606. Bridgens, H. H. June 29. Lithographic printing. - Prints from wood engravings, process engravings, or line blocks are wholly or partly surrounded by a lithographic background in bronze or colour. An impression from the block or engraving is dusted over with pulverized red chalk and transferred by pressure to a finely-grained lithographic stone. The impression is then gone over with liquid gum which is left to dry. The stone around the gummed impression is then treated with a mixture of copal chalk and Russian tallow, applied by means of a suitable rubbing-device, to produce a background as shown in Fig. 2, after which the stone is subjected to the action of gum with a small percentage of nitric acid for about twelve hours. The design is first printed from the block or engraving, and the background in bronze or colour is then printed from the lithographic stone prepared as above described. The process is stated to be particularly applicable to illustrations in trade catalogues.