what is decoupix in crafting?

Answer 1

Do you mean decoupage? This is the french term for a kind of collage made with paper illustrations and glue usually to the effect of making something look either like a piece of memorabilia and quite nostalgic or like a trompe d'oeille piece where the design fools the eye into thinking something depicted there is "real" in an subtle way.

Contrary to the wikipedia definition, I don't think decoupage is very popular, and only a few people who work in craft stores even know what modge-podge is for.

Answer 2

The word is decoupage.
Decoupage (or découpage) is the art of decorating an object by gluing coloured paper cut outs onto it in combination with special paint effects, gold leaf, etc. Commonly an object like a small box or an item of furniture is covered by cutouts from magazines or from purpose-manufactured papers. Each layer is sealed with varnishes (often multiple coats) until the "stuck on" appearance disappears and the result looks like painting or inlay work. The traditional technique used 30-40 layers of varnish which were then sanded to a polished finish. This was known in 18th century England as The Art of Japanning after its presumed origins.
There are many variants on the traditional technique involving purpose made 'glue' requiring fewer layers (often 5 or 6, depending on the amount of paper involved). Cutouts are also applied under glass or raised to give a three dimensional appearance according to the desire of the decouper. Currently decoupage is a popular handicraft.

Answer 3

Decoupage is the building up of different parts of the same image to give a 3D effect.

Decopix is Art Deco pictures used for crafting.