Great work Christopher and much appreciated. I am wondering if it would be possible to add a column for the Naniwa superstones ? Or alternatively intersperse them within the Shapton column or even replace the Trizact column with the Naniwas ?

They are now a mainstream waterstone carried by many of the razor vendors worldwide and seem to be developing at least as large a following as the Shapton glass. The 3M Trizact isn't ....IMO... as important in the razor honing scheme of things.

While it is true that JimR's connection with the man at Naniwa revealed that they are the same as Shaptons there are grits within the Naniwa SS series that are not represented in the Shapton line. For instance the 3k and 10k.