Tob. Reporter, 1987, 114-12, p. 56, ISSN.0361-5693
Cigarette sheaths reduce smoke
U.S. patent 4,691,717 assigned to Dynic Co. The core of a cigarette is covered with a sheath made of material which does not generate any appreciable amount of smoke but burns when the cigarette is sucked. The material is made of starch, agar, gelatin or a mixture thereof.