I've been using Magic chalk for several months...3 hours a day 5 days a week, chalking every shot....the SAME cube. It's down only about 5/16ths of an inch. A little more and I'll just trim the paper down. I'm a swiper so the center does't get drilled.The stuff is harder than any other chalk I've tried yet it works the best. There is so little powdering that hardly any of it gets on my hands, the table, or the cue shaft but miscues are very rare and when there is one I know it's my fault.
I make nothing for this recommendation as I'm only a happy customer. Mitch