How it works varies from museum to museum, but generally, you apply, get permission and follow that museum's rules. For example, in the Louvre, and other museums, painters are not supposed to use the same size canvas as the original. You can't eat or drink in the museum, must use a canvas drop cloth on the floor where you paint on an easel and you must clean up thoroughly after every session. Some museums offer copyists locker space to leave their painting art and gear at the museum instead of bringing everything back and forth each day you want to copy during your month access to a painting art.
