I am inviting on bathroom wallpaper

Welcome to Plaster veneer

In much of the world, plaster veneer is a very rare wall surface. Consequently, it can be difficult to find a local trade worker skilled in the practice. However in some regions, such as Ireland, this situation is reversed, with plaster veneer a common standard, and mud-and-tape the less common alternative.
Unpainted, tinted plaster veneer.

Plaster veneer is well-suited to the renovation of older buildings, since it is an easier option than full re-creation of the original lath and plaster. The veneer surface will closely mimic antique walls, with their hand-applied variations. In contrast, properly finished mud-and-tape drywall can be very planar, and industrially uniform in character. Drywall feels relatively warm and soft to the touch, while plaster feels cooler and very hard. Consequently, plaster veneer might be an appropriate choice in the renovation of an older house with existing lath-and-plaster walls.

Bare mud-and-tape drywall is generally only acceptable as a final decorating finish in utility spaces such as attics or garages. In most rooms, such walls are finished with paint or wallpaper. Plaster veneer walls are usually similarly decorated, but unpainted plaster can also serve as a finish. Because bare plaster can be appealing to the touch, and paint would add an additional layer, some decorators opt to leave exposed plaster in some or all of a room, as a creative choice. In such cases, if the plaster's natural color is not desired, tints can be added as part of the mixing process, or can be introduced unevenly for artistic color effects.