Michael Suwczinsky wrote:
> When I first set this up, I was concerned the flex of the rubber mesh would
> mess with being able to get a flat, stable surface for sharpening, it does
> compress some with pressure, but in years of use the flex and compression
> seem to have no effect on sharpening.

It is possible that your system is actually better - the rubber
provides distributed support for the glass, so the glass is
"as flat as the glass", as opposed to being "as flat as the support".

A similar idea was used in the 30's for surface plates - the glass
was supported by carpet.

A rigid support will (most likely) only support
the glass at a few points, generating forces
likely to distort the glass.

  BugBear