From the seminal moment in 1908 when the young Picasso took a piece of brown card pasted with a "Magasins du Louvre" label and converted it into a new kind of picture, collage has been at the heart of modern art. Indeed, in seeking to transform the discarded scraps and residues of everyday life, the technique found extraordinary new opportunities for subversive rupture, playful artifice, and surreal juxtaposition, together with a completely new conception of the work of art as a material thing. Collage quickly became essential to the idea of the modern, leaving its mark on almost every art movement since, from Dada and Constructivism, via Surrealism, Pop, and Situationism, to the digital techniques of today.