Lath and plaster is a building process used to finish mainly interior dividing walls and ceilings. It consists of narrow strips of wood (laths) which are nailed horizontally across the wall studs or ceiling joists and then coated in plaster. The technique derives from an earlier, more primitive process called wattle and daub.

Horsehair is the long hair growing on the manes and tails of horses. It is used for various purposes, including upholstery, brushes, the bows of musical instruments, a hard-wearing fabric called haircloth, and for horsehair plaster, a wallcovering material formerly used in the construction industry and now found only in older buildings.