A smoking article which comprises a rod of smoking material contained within a wrapper has an air-permeability in a range of from 20 to about 120 Coresta units and is provided in the region of the mouth end, with ventilation means to give a degree of ventilation of 15 to 90%, the ratio of carbon-monoxide yield to tar yield of the smoking article being significantly less than 0.9. If the article has a tip means, the ventilation means may be provided, at least partially, in the tip means. The smoking material may include a high proportion of lamina-leaf tobacco having a relatively high nicotine content. Tobacco in the smoking material, possibly including stem tobacco, is coarsely cut or shredded. The smoking material may include up to 60% of expanded tobacco. The wrapper may contain an addition of a burn-promoting agent.

A smoking article such as a cigarette has a rod of smoking material wrapped in a wrapper of which the substantially uniform air permeability due to viscous flow is not more than 3 and preferably not more than 2 Coresta Units and of which the Do/t value is in the range of 0.08 to 0.65 cm sec.sup.-1, preferably 0.15 to 0.25 cm sec.sup.-1. The length of the rod of smoking material may suitably be within a range of 25 to 55 mm. A reduction in sidestream TPM delivery of 40% or more can be obtained. The invention is also concerned with a smoking-article wrapper material which satisfies the above permeability and Do/t value requirements.

Cigarettes having low efficiency filters, rods of cut filler having a low packing density, and paper wraps having a high net permeabilities and low inherent permeabilities can yield good taste, low gas phase mainstream deliveries as well as low amounts of visible sidestream smoke. Typical cigarettes have relatively large amounts of volume expanded flue-cured tobacco materials as cut filler, paper wraps containing magnesium oxide and/or magnesium hydroxide, and relatively high levels of air dilution.

The sidestream smoke associated with a cigarette or cigarette-like smoking article is reduced by wrapping the tobacco in a double layer of paper. Each layer includes calcium carbonate (i.e., about 30-40% by weight in the outer paper and about 2-15% by weight in the inner paper, the calcium carbonate in the outer paper having a surface area of about 20-80 square meters per gram by the BET method) and a burn control chemical. The outer layer also preferably includes monoammonium phosphate and sodium carboxy methyl cellulose. The calcium carbonate employed has a relatively high surface area per unit weight. The porosity of the outer layer is about 50-100 cubic centimeters per minute by the Coresta method, and may be adjusted by electrostatic perforation.

Smokable rods of cigarettes are manufactured using wrapping materials that incorporate at least one fibrous material (e.g., flax fibers, hardwood pulp fibers and/or softwood pulp fibers) at least one filler material (e.g., calcium carbonate in particulate form). The wrapping materials possess multi-layer coatings. The wrapping materials possess coatings in the form of series of spaced apart bands, each band possessing a series of layers. At least one of the coating layers can have a filler material dispersed or suspended within a film-forming material of that layer. For a representative wrapping material, a pattern of applied to the wire side major surface of the wrapping material substrate as a plurality of layers, and at least one of the layers includes ethylcellulose and calcium carbonate. For that layer, the calcium carbonate is present in an amount greater than the ethylcellulose, on a weight basis. The ethylcellulose and calcium carbonate typically are applied as part of a non-aqueous formulation incorporating iso-propyl acetate, triacetin and lecithin.