Paper wrap of cigarette
Though seemingly innocuous, cigarette paper is largely responsible for the rate at which a cigarette burns and the amount and density of the smoke it produces. The paper displays a pattern of concentric circle striations called "burn rings." The burn rings correspond to two different thicknesses in the paper, which serve to precisely control the speed at which the cigarette burns, slowing it automatically when the smoker is not inhaling in order to prolong the cigarette's consumption and speeding it up as the smoker takes a drag so as to maximize smoke intake. In addition, like the tobacco, the cigarette paper contains a host of chemicals, among them titanium oxide, which accelerates and maintains burning so the cigarette does not go out and the smoke is delivered evenly with each puff. These chemicals have contributed to many cigarette-caused fires, a problem that some manufacturers have not addressed until recently.