Decoupage

Decoupage is a type of collage usually defined as a craft. It is the process of placing a picture onto an object for decoration. Often decoupage causes the picture to appear to have depth and looks as though it had been painted on the object.

The process is to glue (or otherwise affix) a picture to an object, then adding more copies of the picture on top, progressively cutting out more and more of the background, giving the illusion of depth in the picture. The picture is often coated with varnish or some other sealant for protection.

http://en.wikipedia.org/wiki/Collage