These "Wing Cutters" are cheap, zero finishing was attempted. Top right of photo, shows minor flashing from injection molding. Mine had flashing on every seam, step, line, etc. The molds must be made from scrap iron, judging the poor fitting. There for Comfort isn't even a thought with these tools. However they are Copies of a 50yr design, with no understanding what the purpose was, let alone how they worked. The purpose. Allow a half of a razor blade to cut a perfect and repeatable shape in one press and a slight rotation wobble on the long stems end. So it needs a firm seat for the blade that is zero Datum, totally flat! Meaning pressure applied will cut equally. Feather is soft, waxy, slippy and extreme fine, scissors can't even cut them all. This isnt difficult to do, Blade is a carbon steel band, groud sharp, cut then bent. The tolerance is ⅓ of a heaad hair. They only placd the blade into the hot plastic or jig for the plastic to form around the blades. These guys can't stop leaking plastic, so tolerance is a myth. Most important thing is the gap for the Quill... The blade has it, its huge l got a 28 cm goose quill in it. Not exactly the feather type to be used. However my nylon molds had a missing in gap. The other kind of sneered and gave up. last one got over excited and took it to far. Shape? Wing's are Aerodynamic marvel's of evolution, and human Science. These things are an affront to the effort put into our reality, and should not be allowed into ours. Our hobby is to mimic nature. We go to great lengths, this tool is of no assistance in this regard. I have never seen such wing shapes. YouTube tying wing's there are several methods. Origami wing is my favourite looking wing. Wally Wing numerous difficulties. Goose wing is simple a elegant. These lost several nice features, and have no safety gaurd or box. I have to sand them down to dispose of them safely. Disappointed on every front. Card template with a quill grove. Cliip and scissors. Unlimited shapes and size choices. Never know electric trimmer might work well. Waste of money, let's the shop down having them in store. Should never have passed inspection. Imho Oh i read the full instructions on the original design on Ebay this summer. I know how to use them.