During the 1940s and 1950s prefabricated drywall panels gradually replaced plaster as the material of choice for finishing interior walls and ceilings. The earliest drywall panels were used to replace the lath backing in plaster work; they were narrow (16 in. wide) and only 3/8 in. thick. Today, drywall comes in a wide variety of lengths, thicknesses and special-use panels. The low material cost and the large, easy-to-attach panels combine to make drywall the popular choice over conventional piaster.

Plaster-and-lath construction added a lot of moisture to the building, and plastered surfaces had to be left to dry for up to two weeks (depending on humidity, temperature and airflow) before decorating. By comparison, drywall has a low moisture content and the joint compounds used to finish the panels cover only a portion of the surface, not the entire surface, and dry in 24 hours or less. Hence the name drywall (drywall is known by many other names as well, such as Sheetrock — a brand name, gypsum board, plaster-board, wallboard and gypsum drywall).

A sheet of drywall consists of a hardened gypsum core sandwiched between two layers of paper: a strong, smooth finished paper on one side (the face), and a rougher, "natural" paper on the back (see the drawing on the facing page). The face paper is folded around the long edges, which are tapered slightly to accommodate joint tape and compound after the panel is installed. The ends of the panel are cut square and finished smooth, with the gypsum core exposed.