Plastic, mass-produced vac-formed bricks can produce a brick wall much more cheaply than stencilling or carving, but careful painting is required to hide the fact that all the sheets of bricks are identical. Sheets of plastic 'bricks' must be primed and painted to make them look real. Because the sheets are flatter than other means of producing fake bricks, the scenic artists must be even cleverer than normal in how they apply the paint.