Dear Cecil: Certain razor blade companies have been making claims to the effect that "two blades are better than one blade," and show an animation on their TV commercials to demonstrate the "twin-blade effect." Personally, I can't tell the difference when I shave with a razor that has one or two blades. My question is, is the "twin-blade effect" for real, or just so much advertising BS? Also, how many shaves is the average disposable razor good for? I read somewhere that all the razor blade companies use the same steel source for their blades. Is this true? If so, shouldn't all razor blades be of equal sharpness, and hold their edges for an equal number of shaves? Mark H., Scottsdale, Arizona

Cecil replies:

Personally I think the twin-blade effect — technically known as “hysteresis” — is bull, but you can judge for yourself. Twin blades were first incorporated into Gillette’s Trac II “razor system” in 1971. (Ah, for the days when you could buy a razor blade or a bookshelf without having to get some cockamamy “system” along with it.) What you get is two parallel blades placed 0.06 inch apart. When you run the razor over your face, the first blade slides through each whisker and in the process pulls it slightly out of the follicle. Before the whisker can retract, the second blade comes along and slices it off even shorter. Eventually (so the theory goes), the whisker retracts below the skin surface, giving you an exceptionally close, long-lasting shave.

Gillette claims to have done slow-motion microphotography that shows hysteresis actually works. In an Esquire magazine article on this subject some years ago, a spokesman for Bic, one of Gillette’s chief competitors, admitted his firm couldn’t prove hysteresis _didn’t_ work. Nonetheless, years of testing by consumer magazines and by the razor blade companies themselves have never demonstrated any clear superiority for twin blades — at times, quite the contrary. In 1974, Consumers’ Research magazines tested four cartridge razors and found the best to be Wilkinson’s, the only one of the bunch that did not use twin blades. (The Wilkinson blade was good for 40 shaves, compared with 7-10 for Gillette, Schick, and Personna. Big problem for the twin blades: they got clogged up with gunk pretty fast.) A follow-up report in 1977 found the situation unchanged. (Consumers’ Research, incidentally, claimed the average throwaway razor was good for 10 shaves in a 1978 report, but for only 4 shaves in 1981 — a discrepancy it let pass without comment. Gillette and Schick refuse to disclose how many shaves you’re supposed to get, saying the matter is too “subjective.”)

Shave quality, it’s generally agreed, is mainly a function of blade sharpness, beard preparation (whether you get your whiskers wet enough), and how catatonic you are when you do your shaving. Razor construction (number of blades, swivel head versus nonswivel, etc.) appears to be a relatively trivial factor. Still, “two blades are better than one blade” does make a pretty catchy slogan, even if it is basically baloney.

As for what the blades are made of, Cecil confesses he was too lazy to find out exactly where all the steel comes from. But industry insiders admit blades from most of the major manufacturers are pretty similar, with some differences at the high and low ends. Certain Wilkinson blades, as noted, are better, and some low-price house brands are a lot worse. There also technical differences between, say, carbon-steel and stainless-steel blades, although as far the consumer is concerned these may not amount to much. In any case, the fact is that most razor blades today perform pretty much as advertised and don’t cost very much. There are few consumer products about which a similar claim might be made.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.