Papyrus is first known to have been used in ancient Egypt. The Ancient Egyptians used papyrus as a writing material, as well as employing it commonly in the construction of other artifacts such as reed boats, mats, rope, sandals, and baskets. Papyrus is made from the stem of the papyrus plant, Cyperus papyrus. The outer rind is first removed, and the sticky fibrous inner pith is cut lengthwise into thin strips of about 40 cm (16 in) long. The strips are then placed side by side on a hard surface with their edges slightly overlapping, and then another layer of strips is laid on top at a right angle. The strips may have been soaked in water long enough for decomposition to begin, perhaps increasing adhesion, but this is not certain. The two layers possibly were glued together. While still moist, the two layers are hammered together, mashing the layers into a single sheet. The sheet is then dried under pressure. After drying, the sheet is polished with some rounded object, possibly a stone or seashell or round hardwood.