I’ve long had a copy of the book by Leonard Koren shown at the bottom of the piece in wikipedia. I really have no other training in the concept other than what I could see at Japonesque. Somehow, I think, it should be no other way. Similar to @Harp I have restored some old tools and they are really only beautiful when I have managed to preserve the integrity of their history. When something has worn with time, it becomes somehow less provocative or comforting when its flaws are concealed. The effect it has had on me and my sensibilities has lasted for decades now. An excellent furnituremaker I used to work with jokingly described it as signature. That is, when you make a mistake, it becomes clear that the piece was made by a human. Whenever I mess something up, it is pretty liberating to think of this as one of the possible options available to me to sign the piece. Lastly, it dawned on me, years after reading the book, that, as a woodworker in particular, revealing the true nature of the material (literally wormholes and all) is showing the deepest respect and understanding to something organic. This seems very zen to me to let go of all you have been taught in order to see the beauty of the truth.