DECORATIVE BACKING, PARTICULARLY FOR ARTIFICIAL GEM STONE WITH COLOUR EFFECT AND METHOD OF PRODUCING SAID EFFECT FOR DECORATIVE TRANSLUCENT BACKING Russian patent published in 2013 - IPC B44F1/04 

FIELD: process engineering.

SUBSTANCE: invention relates to gem stones processing. Decorative translucent backing comprises layer on its back side. Note here that said layers are deposited and arranged in the following order from backing rear side: optically modified 2-80 nm thick layer. Note here that said layer is composed of at least one element of oxide from group including Gc, Si and oxides Ti, Zr, Nb and Al alloyed alternatively with the other elements. Reflecting layer composed of at least one metal or alloy from the group including Au, Ag, Cu, Al, Cr, Ti, aluminium bronzes and alloys Au, Ag and Cu in thickness that allows maximum possible reflection of incident visible light depending upon spectral reflectance of reflecting layer material back into translucent backing. Finally intermediate 10 to 100 nm thick layer. Note here that said layer is composed of at least one metal of the group including Ti, Ct and Cu and one layer of protective lacquer.

EFFECT: combination of optically modified layer and reflective layer, selective reflection of visible light in and from the stone.

15 cl, 2 ex