Scott, I wondered if it might be them, certainly at .7m - the design looks superb. Can you mention the price of the blank, as they don't list any on their website? I think we know this is a custom order, BTW.

Mike Lockwood recently mentioned them but SFAIK he hasn't worked with any, a good place to ask is here on Yahoo.

I do agree about the finishing/blank ratio for large mirrors (mine is right around 2:1 typically, excluding coatings), it's what drives me to use quartz exclusively but consider cellular as my size range increases (though there's hope for larger quartz blanks). That is to say, the price of the blank is a fraction of the price of the mirror, and improvements in performance from using a better substrate are an easy sell.

What do they mean by the gravity loading aspect, though? Is that referring to the FEM design for ribbing and support?

Dave, I contacted "embeddedrf" last year and they eventually told me they weren't sure if they were going to be going back into production - those prices are really old (see wayback machine for 2002) and no longer valid...

Is this a thread hijack in process? Maybe should start a new one.

Best,
Mark