Painted writing steel carries a coil-applied coating. Ceramic writing steel carries vitreous enamel, which is glass fused to the metal at high temperature. The distinction is not a marketing gradation; it is a different material on the surface.

The consequence is scratch and ghosting resistance. A marker, a duster or a fingernail can eventually abrade a paint film, and once the surface is microscopically roughened, marker pigment lodges in it and the board ghosts. Enamel does not abrade in normal use, which is why school boards written on daily for a decade are made from it.

Painted steel is the correct answer where the board is used occasionally and price leads: an office meeting room, a hotel function space, a retail range. Ceramic is the correct answer where the board is in service six hours a day for years. Specifying the second where the first would do wastes money; specifying the first where the second is needed produces complaints in year two.