“Moist lips are thrilling lips! Keep them soft, alluring.” So proclaimed a 1936 ad for a novelty cigarette, designed for women. At the time, almost all cigarettes were unfiltered. Companies sometimes added special mouthpieces — called beauty tips, often made of cork — for women. After all, what seductress would want to be seen picking tobacco flecks off her tongue? In the early 1950s, when scientific reports showed just how dangerous smoking could be, tobacco companies scrambled to add mouthpieces to most cigarettes, hiring labs at Dow and DuPont to design them. In 1952, the Kent Micronite came equipped with a filter that sucked particles out of the smoke — “Here’s proof you can see. . . . Kent gives greater protection than any other cigarette,” the ad read. But the Micronite contained asbestos fibers that were far more dangerous than tobacco smoke. Philip Morris promised that an antifreeze chemical (diethylene glycol) in the mouthpiece would take “the FEAR out of smoking.” And DuPont scientists tried to trap harmful particles with new fabrics, including Dacron, the same polyester that allowed for wrinkle-free pantsuits.

But synthetic fibers in cigarette mouthpieces created new problems. In the 1960s, Philip Morris scientists noticed that mouthpieces shed tiny fibers that could be inhaled into the lungs. The industry called it “fallout.”

Even when filters weren’t toxic, scientists realized that any material that effectively trapped particles also weakened the cigarette’s kick. Today most manufacturers use a method called ventilation to dilute the smoke: the paper wrapper, perforated from end to end by a constellation of tiny holes, pulls in fresh air. But studies have shown that smokers now drag harder to compensate. “It’s like saying you’re going to have the same bowl of ice cream, but you’re going to eat with a very small spoon,” says Bradford Harris, a Stanford graduate student who reviewed industry documents discussing filter problems.

Image In the 1950s, an RJ Reynolds chemist named Claude Teague developed a filter that turned from white to brown, providing, he felt, comfort to smokers who assumed they were seeing dangerous particles kept from their lungs.

Even now filters don’t make cigarettes safe, though many still come wrapped in paper printed to look like cork — a throwback to that carefree era of inhaling, when the big worry was smeared lipstick.