Wiktionary
n. An art technique in which pieces of flat material (paper, oilcloth, etc.) are pasted into a painting in much in the same way as a collage, except that the pasted pieces represent objects in the painting.
Wikipedia
Papier collé (French: pasted paper or paper cut outs) is a type of collage and collaging technique in which paper is adhered to a flat mount. The difference between collage and papier collé is that the latter refers exclusively to the use of paper, while the former may incorporate other two-dimension (non-paper) components. As the term papier collé is not commonly used, this type of work is often simply called collage.
Cubist painter Georges Braque, inspired by Pablo Picasso's collage method, invented the technique and first used it in his 1912 work, Fruit Dish and Glass. Braque continued to use the technique in works such as Bottle, Newspaper, Pipe, and Glass. Other notable artists who pioneered this technique include Kurt Schwitters, Henri Matisse, and Robert Motherwell.
Papier collé is sometimes also used to refer specifically to the paper collages of the Cubists.