Quote Originally Posted by William Fretwell View Post
Wth the exception of his convex sharpening stone with blades moved at 45 degrees to give a concave edge the rest is very standard.
He does emphasize rounding and tailing off of the corners of plane blades to avoid edge marks. Easy to do freehand, no jig used of course. His flattening plate was far from flat as he demonstrated with a ruler.

The wooden concave edge model is showing the result you would get from using a stone that is not flat, and the the not-flat diamond plate is demonstrating that you have to check for flat. Those are teaching aids.