Picasso did it with swagger (and of course glue). Around 1912 he stole the pasted-paper idea from Braque. “After having made the papier collés, I felt a great shock,” said Braque, “and it was an even greater shock to Picasso when I showed it to him.”
But where the other cubist had used art-ready cut papers, Picasso scavenged. Sheet music, newspaper scraps, the label from a packet of tobacco, cloth. The contrast of the real stuff with the painted forms was new. For the collage above, Homme á la Pipe (Le Fumeur), 1914, he ripped a piece of the old wallpaper off his studio wall and stuck it on the canvas. Warch a short MOMA video about the materials in Picasso’s early collages here.
“Stuck on you.” At the time, in France, collage was slang for “living in sin.” In his excellent Collage; The Making of Modern Art, Brandon Taylor says that Picasso’s early collages provoked a “frisson of excitement at the sight of a coupling…illicit…at the very limits of aesthetic decency.”