TomD
OK, found some stuff online, but it wasn't my preferred method. So...T

ake your weak hand and hold it relaxed at your chin as one does simply by bending at the elbow. Extend the middle finger in the familiar jesture and moisten the end liberally. Touch that finger to the thumb as if testing for a medium rare steak. Now hold the razor horizontal and at the lowest angle you believe could catch the nail. If the edge is properly sharpened Wichita sharp it will hook the nail, when the razor is advanced in the direction of the face across the surface of the nail. This is done with a very light touch, and there is no damage to the nail. Unlike cutting hair, a barber can do this all day and not affect his nail.

For Arkansas sharp, you extend the middle finger... with the palm to the face. You moisten liberally, and leave it extended. You bring the razor across the surface of the finger, ona tangent path, and if it catches on the flesh, it is sharp in the spot tested. Again there is no damage done to the skin and the test can be repeated at will.

So, this method is described as for razors. Woodworking tools are far heavier on occasion, and dropping one in the position described, could cause serious damage to the supporting, weak appendage. So if you use this method use it at your own risk, and place your hands in a safe position fitting any tool you are then using. It will work so long as the angle of the approach is low and tangent to the dome of the tip of the digit. I love this method for 2 step finish sharpening, or one step if you are using something really aggressive that will do it in a single step. If you are refining through several stages of finishing, this method will not work, but in my experience often wire edges don't either since they are very slow to come up in some circumstances with the finest stones.