The exterior walls of buildings and sidewalk sheds serve as billboards for brands and canvases for street artists in New York City.

Brands plaster ads across these surfaces in a form of guerilla marketing known as "wild posting" or "wheat pasting." Street artists tear them to create collages, and the organic processes of decay further transform them into arresting images.

Creating artworks from ads and posters dates at least to the 1930s, with Walker Evans' photograph "Torn Movie Poster" (1931) and Aaron Siskind's close-ups of textured walls. In the 1950s, future members of the Nouveau Réalisme movement - notably Raymond Hains, Jacques Villeglé and Mimmo Rotella - pioneered the techniques of décollage and affiches lacérées, by layering, tearing and mounting posters onto canvas.