Paper, whether produced in the modern factory or by the most careful, delicate hand methods, is made up of connected fibres. The fibres can come from a number of sources including cloth rags, cellulose fibres from plants, and, most notably, trees. The use of cloth in the process has always produced high-quality paper. Today, a large proportion of cotton and linen fibres in the mix create many excellent papers for special uses, from wedding invitation paper stock to special paper for pen and ink drawings. Formed from wood pulp or plant fibre, paper is chiefly used for written communication. The earliest paper was papyrus, made from reeds by the ancient Egyptians raw pulp contains an appreciable amount of lignin and other discoloration, it must be bleached to produce light coloured or white papers preferred for many products. The fibres are further delignified by solubilizing additional lignin from the cellulose through chlorination and oxidation. These include chlorine dioxide, chlorine gas, sodium hypochlorite, hydrogen peroxide, and oxygen.