A method of producing photographic pictures on plates or panels formed of compressed wood fibres

摘要

568,253. Photographic processes. KOOPERATIVA FORBUNDET FORENING U.P.A. Feb. 11, 1944, No. 2579. Convention date, Dec. 21, 1942. [Class 98 (ii)] A fibrous plate of compressed wood fibre is impregnated with a colloid (e.g. glue, gelatin, or albumen) sensitized with a chromium salt (e.g. a bichromate), is exposed to light, the soluble colloid removed by washing with hot water, and the whole upper surface of the plate inked (e.g. with asphalt lac), the colour being only absorbed by those parts of the plate where the colloid has been removed. In a modification, the plate may be first impregnated with the colloid, and then treated with bichromate solution. The Specification as open to inspection under Sect. 91 refers also to the incorporation of a silver salt in the colloid and subsequent hardening development. This subject-matter does not appear in the Specification as accepted.