GB625425A - Improvements relating to producing designs on support members - Google Patents

Abstract

625,425. Ornamenting. SOBY, W. May 4, 1946, No. 13559. [Class 93] [Also in Groups XVIII and XX] A process for producing designs on a support, e.g. name and number plates, scales and dials as for radio or television receivers, includes the steps of applying desired markings to said support, coating the support with pigmented lighthardenable material, exposing said material to light through a transparent screen having opaque areas surrounding said markings, and washing out the unexposed parts of said material to provide the markings with surrounding areas which are not coated with said pigmented material. Typically a clear glass blank is cleaned with stannous chloride and precipitated chalk, coated with a bichromated albumen preparation, and exposed through a negative bearing the desired markings, e.g. station names. The plate is next coated with a thin layer of resin and castor oil in naphtha by spraying the plate, developed in water, and powdered colours are brushed into the markings, excess being removed with cotton wool under water, and the plate is dried by spinning. The plate is then coated with a pigmented albumen - or casein - bichromated material by spraying, a translucent effect being obtainable by spraying semi-set material. This material is then contact-printed through a transparent screen having opaque areas in register with the markings previously printed on the plate, and the plate developed by washing to leave the markings surrounded by transparent areas on a dark or translucent ground. Instead of glass the support may be of celluloid, artificial resin, or metal. The Provisional Specification refers to employing a colourless light-hardenable material sprayed with a coloured laquer to give a translucent effect as an alternative to the pigmented material.