Here is a link to a chart of grit sizes

http://www.toolsfromjapan.com/store/index.php?main_page=page&id=13&chapter=5

Sharpening can become a marital art of extremes, a 13,000 polishing stone is getting close to ultimate, some people use mdf charged with buffing compound as a hard strop to avoid a comparitavely soft leather strop in hopes to prevent rounding.