Good find. I had not realized that AudioDiscs went back into the glass business in 1951. I guess I could have seen them listed on their price list. If all you needed the disc for was to bring it over to the plating room and have it electroplated, then glass was ideal. But despite that currently and in the past couple of decades there are very few people who use lacquers for any other purpose, I don't think any of the few remaining lacquer manufacturers have glass base discs in their product line. (Scratch jocks cut their "dub plates" on uncoated vinyl.) Mike Biel [log in to unmask] From: George Brock-Nannestad <[log in to unmask]> From: Patent Tactics, George Brock-Nannestad > Hello Mike, > to your very thorough discussion of glass vs. metal I can add the > following reference: > Audio Record Vol. 7, No. 3, pp. 1-2, March 1951 > - this is the magazine of Audio Devices, and they discuss the advantage of having the much smoother surface of glass to use as a base, and they sound clearer. Surface roughness graphs of iron, aluminum and glass are shown (and if they have not cheated), the glass is very much smoother. They claim that their process is much improved over the wartime ones. > Audio Record may be found on the internet archive. > Best wishes, George