Cellophane

Cellophane is a thin, transparent sheet of regenerated cellulose valued for its low permeability to air, oils and bacteria, which makes it useful for food packaging, though it remains highly permeable to water vapor unless coated. The Swiss chemist Jacques E. Brandenberger invented cellophane in 1908 while working for a textile company, reportedly after being inspired by a wine-stained tablecloth, and patented his manufacturing process in 1912 following several years spent perfecting it. The film is made by dissolving cellulose from wood, cotton or hemp in alkali and carbon disulfide to form a viscose solution, then extruding it through a narrow slit into an acid bath that reconverts it into solid cellulose film, which is subsequently cleaned, bleached and softened with glycerin; beyond food wrapping, cellophane has also served as the backing for adhesive tapes such as Scotch Tape.