Diamondwood is a good choice. Works well on slate and glass. No so much on metal surfaces. It can get screechy. Diamondwood is also limited in supply. Not much of it left out there. The plant that made it, burned down several years back. They never rebuilt. The formula is protected by patent, so nobodies reproducing it. There is another product thats making its way into the market. Called Dymalux. It's pretty close. I picked up a supply here awhile back, and been running it on multiple surfaces. Been happy with it so far. I know alot of guys are hot for Snakewood. But it's hard to get too, and not cheap either. Personally, I think guys put too much efficents on the sound, when it's the vocabulary you should be worried about creating. If your on facebook, ck out my call page, Scott's Custom Turkey Calls. Be glad to help ya if your wanting something.