A method for increasing the firmness of a pillowtop or any other soft mattress. The method includes providing a rectangular sheet of cotton fabric material having hook fasteners on one end and loop fasteners on an opposite end to attach the sheet of material around the mattress. The firmness of the mattress is increased by tightly wrapping the sheet of material around the mattress using the fasteners. The sheet of material is sized appropriately to fit entirely around the mattress with overlap. Preferably, the sheet of material is sized and manufactured for wrapping longitudinally around the mattress.