- Drywall (also known as plasterboard, wallboard or gypsum board) is a panel made of gypsum plaster pressed between two thick sheets of paper. It is used to make interior walls and ceilings.
- A plaster board is made of a paper liner wrapped around an inner core made primarily from gypsum plaster.
- The raw natural gypsum, CaSO4·2 H2O, is heated in a process called calcined to produce the hemihydrate of calcium sulfate (CaSO4·½ H2O) this is done in kettle or flash calciners the plaster is mixed with fiberglass, plasticizer, foaming agent, finely ground gypsum crystal as an accelerator, EDTA, starch or other chelate as a retarder, various additives that may increase mildew and/or fire resistance, wax emulsion or silanes for lower water absorption and water.
- Plasterboard is commonly made with one of three different edge treatments—tapered edge, where the long edges of the board are tapered with a wide bevel at the front to allow for jointing materials to be finished flush with the main board face, plain edge, used where the whole surface will receive a thin coating (skim coat) of finishing plaster, and finally bevelled on all four sides, used in products specialised for roofing.