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Exactly the opposite of what you want,,,

The back of the thumbnail trick, actually works way better then either the pin or the toothpick as you don't miss any of the edge... Try it yourself,...

Yes a toothpick will work,, so will the flat of a thumbnail for the same test..
Just lightly drag the top of yer thumbnail from spine to edge and if it catches at all you have a wire edge...

The...