Search:

The bit about feather blades caught my eye.
Glass -- hmmm....
Yet some do "cork" a harsh edge....
i.e. run it lightly on cork so it shaves
like day two or three.

Feather blades... love em or...

This is a lot like a newbe stropping a "shave ready" razor.
The risk is larger than the gain so it is discouraged.

Any test that needs to be learned needs to be in the list
of things to...