 In other projects, he has bricked up the entrance to gallery spaces, rendering them impenetrable for the duration of the respective exhibition, and has painted the words " Ne Travaillez Jamais" on the wall, a phrase lifted from the May, 1968, protest riots in Paris.When Tiravanija does make objects, they are most often multiples and ephemera connected with exhibitions.Since the early 1990s, Tiravanija has published multiples in the form of backpacks, cooking utensils, and maps as part of his practice.