GB456968A - Improvements in the production of line gratings such as for relief or colour photography - Google Patents

Abstract

456,968. Printing-surfaces. THERIAT, J., 41, Rue Billaut, La Courneuve, Seine, France. Feb. 14, 1935, Nos. 4794 and 4795. Convention dates, Feb. 14, 1934 and Jan. 8, 1935. [Class 100 (ii)] Gratings for use in relief or colour photography are prepared by printing on a transparent support with a printing block consisting of a number of blades piled against one another, alternate blades projecting beyond the intermediate blades and having their surfaces planed to a common level. Ink or colour may be applied to the raised edges or to the grooves between them. Fig. 5 shows a portion of a block for use in printing multicolour gratings and Figs. 1 and 2 separate blades thereof. A number of rectangular blades 1 are piled together with intermediate blades 2, 3, 4 having recesses 5<1>, 6<1>, 7<1> in their upper edges. All the blades are provided with registering holes 5, 6, 7, Figs. 1 and 2, forming passages for the supply of inks of different colours the holes 5 of the blades 2 communicating with the recesses 5<1> by slots 5a, the holes 6 of the blades 3, with the recesses 6<1> by slots 6<a> and the holes 7 of the blades 4 with the recesses 7<1> by slots 7a. A transparent sheet, e.g. of aceto-cellulose, is pressed against the block and receives bands of different colours separated by non-printed bands of the same width. By moving the block laterally of the bands to the extent of one blade width and applying three different colours, the sheet may be printed with different colours on the previously not printed bands and a grating of six different colours thereby produced. Instead of a flat block circular blades may be piled on a mandrel to form a roller.