reason...
I think if you need to label your cranks, you have too many and aren't familiar with them, not a recipe for success, but to each his own.
?? you lost me on your post?? "not a recipe for success"... huh??
since it doesn't negatively affect the crankbait in any way, i think if you are fairly new to fishing, and it helps you learn your baits better....it gives you a quick "reminder" to help you. what is the harm? to me, that could be a "key ingredient" in your recipe for success...quicly being able to identify and know the depth at which a certain crank runs...