Inert substrate, looks great, cheap if you can find it. Debate on its abrasiveness, but there are some macro shots of it on the forum that show its really not that sharp. There are metallic flecks but nothing really to worry about. The only thing is that some report an oil slick type appearance on the top, but most claim to not have this issue. Probably depends on where you get it from (ie, which state it was made).