I don't remember ever seeing this method for punching coro. I started a project today that requires me to punch a TON of holes in coro. After playing around for awhile figuring the best way to do this, I pulled out my handy dandy, WAY old, cheap, $5 special, soldering iron that I burn holes in my stobe lenses with. Using this is just as fast as an awl or drill, just much cleaner. No where near as much push through on the material. Very easy, and not hard to do at all. Wish I would have thought of this a few years ago.