Quote Originally Posted by Grazor View Post
Have seen that but not tried his techniques.
I would regard the glass as "killing" the edge, and bread knifing for chip repair and taking out a frown etc.
Three things are being discussed here.

1. Bread-knifing is, as you said, for edge re-programming.

2. Killing on glass is to deliberately dull the edge in order to help a beginner be able to assess when he has brought the edge back. When the bevels are set the edge feels sharp again.

3. Jointing is not, in my opinion, the same bread-knifing. Jointing is done (in theory) to remove the saw-toothed edge that is the result of bevel scratches reaching all the way to the apex of both bevels.