§ Positioning · 01.00 A plastered wall is a building element. A painted-over drywall wall is, at best, a surface treatment. The difference matters because architects and interior designers specifying a wall are choosing between a material and a coating.
Plaster is mineral. Limestone, gypsum, lime — earth pulled from quarries, mixed with sand or marble dust, troweled wet onto a substrate, and cured into something dense, breathable, and dimensional. The wall holds light differently because the wall is the surface, not because something has been brushed onto it.
Drywall is a paper-faced gypsum board, taped at the seams, primed, painted. The painted surface is what you see; the paper underneath is what you don't. Move a hand across it: the friction is paper. Move a hand across plaster: the friction is stone.
This is evergreen reading for specifiers. The wall you write into a spec sheet should be the wall the room deserves — a material, not a finish.
