Process for producing decorative or informative patterns on objects formed of singly or multiply plated metal sheets

DETAILED DESCRIPTION OF THE INVENTION The application of the teaching claimed will be described in the following example.
From plated sheets manufactured from two different aluminium alloys stoppers, ornamental caps or similar parts, e.
g.
for cosmetic products, are formed by coldworking methods.
This can for example provide on the outside a highly polished layer and on the inside a less polished layer.
In the course of subsequent treatment of the blanks, parts of the outer layer corresponding to the patterns are removed by known processes, so that articles result whose outer surface is interrupted by the lower surfaces of different composition.
If such an article is now put into a surface treatment bath and there, e.
g.
, chemically or electrolytically polished, and possibly also anodised and coloured, the treatment in one and the same bath is enough by itself to give highly-polished and matt surfaces side by side, in the above-mentioned case with the highly-polished layer on the outside and the matt layer on the inside.
Such effective differences are in great demand in many ornamental devices, decorative or informative or advertising parts and objects of applied art and sign plates of all kinds.
Conversely one can of course, by suitable choice of the plated layers, make the outer raised layer matt and the inner one highly-polished.
Here too what matters is the use of one and the same bath with which the layers react differently.
A particular advantage of the procedure claimed is that the individual articles can be economically finished in a single operation.
For this one can make use in particular of chemical and electrolytic polishing processes which lead, for example, in one and the same bath, owing to the different materials of the layers, on the one hand to polished and on the other hand to entirely matt surfaces, or to surfaces that are only differently polished.
The individual plating layers can e.
g.
consist of aluminium of different purity, for example on the outside an aluminium material with between 99