Models who pose nude for student artists in Philadelphia are to join a trade union to protest against poor pay and conditions.
Models at the Moore College of Art and Design complain $7 an hour is not enough for sitting around naked in cold rooms, full of paint fumes.
Claire Hankins, 39, who is leading the move, said: “We were at a loss about how to get the schools to pay attention to us.”
The college argued that the models had no cause for complaint, because they were effectively independent contractors.