Actually it is lacquer and a tissue material I get from Japan. Multiple layers of lacquer. It is time consuming and you do need to deal with noxious vapors. The lacquer over the labels is clear so it shows the labels through the lacquer and the other three sides have additional black lacquer coatings.
I will probably keep this stone for my own use. The knife after flattening glides nicely over the crack. Actually as Aoto goes, I really like the stone
Glad I put it back together.
Shinookami, you are getting a whole stone, not a rebuild
I don't think anyone would like a tar coated stone
Might ruin the stone since it would be oily.
Actually you can see the saw marks through the lacquer, which is a sign of a stone's authenticity.