Not only a special course but years of on the job training. For the first couple of years, a beginner will confine himself to no less than 26". After that, 25" then 24" and so on until, when he feels he can handle it, 22"! That's an exciting day; let me tell you! I've been at it long enough, I can cut a 28" blank right in half. A really old guy, like Sorensen, has gotten to the point he can cut off 22" and end up with a six incher. I can but dream. Regards, Bill.