Blade thickeness, or bead diameter also depends on barrel length, ie: distance from your eye to the front blade or bead.
The shorter the barrel, the thinner it can, or visa-vis. Depends on what is needed for visibility. The top- rear corner, if cut
at a 45 degree angle & polished, will give a bright spot for aiming in the dark bush or on dark targets. Out in the open sun,
a swipe with a dry erase marking pen will make a dull black sight, not shiny at all. A simply wipe with the thumb of finger
will wipe off the dull black and leave your front sight shiny again.