Probably not so much a sharpening tutorial as a treatise on abrasives.
I have been meaning to do this for a very long time. I will eventually make a video going over the basic principals of sharpening.
The purpose of this is to counter some misconceptions and misunderstanding and also to provide an introduction to abrasives for anyone new to the subject, or indeed as a refresher for the more experienced.
It is still somewhat a work in progress but this is pretty much it in essence, with maybe some editing. I will probably add some more references as well but that is fraught since many of them come and go over time.
It is quite long but there is a lot of material to cover.
There will eventually be a YouTube video but that will require some planning.
https://docs.google.com/document/d/1MsXvMZ5ISZxjxvqt0FepLhsQKLw4_WsMnGq1auMtfSk/edit?usp=sharing