Abstract: The calcium carbonate filler level or the basis weight of a paper wrapper for a smoking article is varied to enable the designing of smoking articles with specific characteristics including a specific puff count, tar delivery and carbon monoxide delivery.

Abstract: A variable dilution cigarette of the type having relatively rotatable filter segments for controlling dilution is provided with stops. Spaced-apart stop elements are provided on one filter segment and a tongue-like engagement element is provided on the other filter segment extending over the first segment between the stop elements. The edges of the engagement element engage the edges of the stop elements to limit rotation.

Abstract: A variable dilution filter cigarette is provided which includes a substantially cylindrical tobacco rod, an axially aligned, substantially cylindrical filter plug wrapped in a substantially air-permeable plug wrap, and a substantially air-permeable first layer of tipping paper which joins the filter plug to the tobacco rod. Circumscribing the first layer of tipping paper is a second layer of substantially air-impermeable tipping paper. The second layer has a circumferentially extending row of closely spaced perforations intermediate its two ends which divides it into a mouth-end sleeve attached to the first layer at the mouth end of the cigarette and a second rod-end sleeve detachable from the mouth-end sleeve.

Abstract: This invention relates to a filter cigarette having inlet vents in the filter mouthpiece divided into two groups. The distance between the two groups of inlet vents is selected to give an increased resistance to draw without appreciably decreasing dilution or total particulate matter.

Abstract: Humic acid-dyed paper suitable for use as wrappers for smoking articles is post treated with magnesium sulfate to fix or render the humic acid insoluble. Paper treated in this manner provides a product of acceptable brown color. Smoking articles wrapped in the treated paper evolve a reduced amount of carbon monoxide on smoking under normal conditions in comparison to currently available brown papers stained with humic acid.