Ken Lowther wrote: > Wasn't there an article in S&T where the author of an article suggested > that at some point thick mirrors may actually be more of a problem to > support well than a thin one? FWIW I have two 14.5" Pyrex mirrors, one is 2.5" thick and the other 1.4". The 2.5" is a much worse "slumper" than the 1.4". Bill Tondreau