Disposable shavers are great but I find it hard to remember how many times I have used one as I don't wet shave evry day.
So
a) A sequence of liitle break off tabs or a clicky non-reversing slider. Move up one notch each time U use it. When all postions gone, discard razor and get a new one.
b) Some sort of water sensetive dye that eventually hydrates and changes colour after "n" wet -and - dry - out cycles.-- 8th of 7, Jun 12 2002 Goddess shaving http://www.gillettevenus.com/... for the blissmissbits [drew, Jun 12 2002, last modified Oct 21 2004] b) is baked. Gillette use this system.-- drew, Jun 12 2002 Could also be useful in finding out if your girlfriend/housemate/mum is using it to do her legs/arms/other (mum + other = *shiver*).-- sild, Jun 12 2002 surely the discard decision is based upon the sharpness of the blade, rather than its age. ie. couple of partial shaves (having a HUGE mutton chops phase) will wear the blade less than a fulll on baldy top phase.-- mymus, Jun 12 2002 You could just have a standard soft-grip handle that you put the complete razor into, and then click out, one section at a time. You would have an open section that would show how far down the thing it was, and the last click would need to be half way up the handle, to allow proper control.-- [ sctld ], Jun 12 2002 I swap blades every Sunday.-- waugsqueke, Jun 12 2002 Bliss - see link.-- drew, Jun 12 2002 Might I suggest changing the blades when they cease to be sharp enough to give a good shave? No other indicator would be as accurate.-- pottedstu, Jun 12 2002 'stu, I find that on average, a week's worth of shaves is about it for the blades I use (Sensor Excel). That may vary by a couple of shaves here and there, but it's close enough for rock and roll. It also solves the problem of remembering when I last changed the blade.
bliss, indeed. (So now we know the secret of the Katie Couric legs, hm?)-- waugsqueke, Jun 12 2002 [bliss] How so? I use the Mach3 version and the indicator strip works, just like it says on the can.-- drew, Jun 12 2002 I generally just try it on the cat first.-- IvanIdea, Jun 12 2002 turnable portion of the handle that moves past a sequence of numerals 1-10 etched on the static portion.-- po, Jun 12 2002 I don't do the 'downing a rain forest' thing anymore, and at Mach 3 it doesn't do to point the nose at the ground :-)
Razors in a can? Nah, in the bathroom. Left of the sink. Don't know why, they just are, OK?-- drew, Jun 12 2002 po, that's an egg timer you're describing, surely?-- drew, Jun 12 2002 Apparantly, if you put a razor blade in the exact center of a pyramid, it will stay sharp for more than 1/3 more time than an un-pyramidised one.-- [ sctld ], Jun 12 2002 'tis well known and researched, and yet no-one knows why.-- drew, Jun 12 2002 yes and yes-- po, Jun 12 2002 But of course the logical(?) extension is to provide a digital display and buttons in the handle of the Mach3 that tracks usage (click the button), sounds an alarm when the blade is history, and... has a handy clock so you know you're running late for work (assuming, of course, you can figure out how to set it. Otherwise it just blinks like the VCR and collects soap scum)-- jayhawk, May 30 2003 random, halfbakery