Shaving the truth
Gillette's scientists say that all blades are roughly 0.00006 of a millimetre thick along the cutting edge.
Beards differ and it's the positioning of the blade - in relation to a hair not its thickness - that determines razor life, they say.
Equally mystifying to legions of male shavers, at least, is why blades seem to deteriorate instantly when they are used by women.
Mark Conley chucks his blade as soon as he finds out his wife has used it on her legs.
He has touched on a shaving truth.
Women use their razors less often than men, so when they do get around to shaving, the hair on their legs is longer than men's beards. That causes razors to wear out more quickly.
Also, women often shave with water and soap, which is less lubricating than shaving cream.
Robert Porter recently found a way to beat the battered blade syndrome. He used to switch blades every Monday and Thursday, but not since purchasing a RazorMate.
"I've read all the documentation and the testimonials," he says, quoting that blades go dull because they bend with each use. His current blade, he says proudly, is still sharp after a week of use.
Cynics have also wondered if the moisturising strips on disposables are part of a plot by companies to force shavers to toss their blades sooner than needed.
The bands of polyethylene oxide that are activated by water to reduce friction often give out before the blades, making razor blades look worn out.
Blademakers say "no way. Moisturising strips do break down much faster if a razor is left sitting in hot water - the hotter the water the quicker the deterioration".
Years ago companies were more forthcoming about blade life.
A 1905 Gillette ad promised "10 to 50 delightful velvety shaves without stropping."
Another manufacturer, Rolls Razor, offered a blade in 1940 with a "semi-automatic strop and hone," promising it wouldn't wear out in 10 years.
The razor may have been too good: Rolls went out of business.
More about the truth
Judge Hall determined that Gillette's claim that the M3Power raises hair up and away from the skin is both "unsubstantiated and inaccurate".
The court found that that the product demonstrations in Gillette's advertising are "greatly exaggerated" and "literally false."
Saturday Night Live Parody
Back in 1975 "Saturday Night Live" spoofed the Gillette Trac II razor with a triple bladed product it called TripleTrac. Gillette marketers still wince at the parodied slogan "Because you'll believe anything".
Gillette really did shift to a three-bladed razor, christened the Mach3.
The company spent six years and over $750 million bringing the product to the marketplace, nearly four times the amount it spent on the 1999 launch of its Sensor razor. The first year's marketing budget pushed the upfront cost to more than $1/2billion.
The cutting edge - Gillette's flashy Mach 3
Read this article in The Slate penned by Thomas Hine.
Bring on the Mach3
The biggest hurdle Gillette had to overcome was charging 35% more for Mach3 blades than it did for its top-of-the-range Sensor range.
To address the perceived higher individual blade cost Gillette marketed the Mach3 blades in packs of four and eight as opposed to five and 10 for its Sensor range.
Three or four blades? More? What gives the best shave? Read this California Screamin' satiric article think about it.
Blade Life? Don't Ask!
Gillette brags its blades are "The best a man can get" but for many men there is a more pertinent question "What is the most shaves from a blade a man can get?"
Men shave on average just over five times each week. Experts have determined that over a lifetime the average man shaves nearly 27 feet of hair off his face.
Women use their razors less than ten times a month, but shave more than nine times as much skin area.
That adds up to a lot of scratchy blades. But neither Gillete, which dominates this market, or other manufacturers, offer guidance on when to throw a blade away.
It is no accident that shavers are working in the dark. To John Darman, Gillette's vice president for blades and razors, disclosing when a blade loses its cutting edge is a touchy subject.
"What if the only ones who listen to us are the ones who are currently changing more frequently?" Mr Darman asks.
Moreover, Gillette maintains a maze of laboratories dedicated to whisker research. Its scientists can wax on about the "Hysterisi Effect" - how long it takes a whisker lifted by a passing blade to snap back to the skin (one-eighth of a second) - or the "lubricious value" of shaving gel (up to twice as slippery as shaving cream).
They can also describe the ideal beard length for shaving (about 24 hours worth of growth, just after the hairs have cleared skin level.)
Thomas Buell generally scrapes along for two or three weeks with a single blade.
"By 5pm I'm not an ape or anything," he insists. But he does have a cutoff point: "First blood, that's my rule."
Edwin C Jeffers, who ran a barber shop for 15 years, remembers that a well-stropped straight razor would last indefinitely.
He is now retired and uses disposable razors that he says last up to 10 days. Not everyone can do that, though, he says. "I've seen guys with hair so squirrelly, it's just like wire," he says, "that'll knock the edge off a blade real quick".
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