Flake over grind. Not my cup of tea but it doesn't waste much rock and produces art. Jesse and Curt(piper) could probably explain the process better than I. From what I understand it's an efficient use of rock and produces exquisite pieces, but I like the idea of starting from a spall and going to a point. If I had some rare, perdy stuff, I might consider it. The guys that do it certainly produce results!