Old Virgin or New Virgin

This eye catching title is about Virgin Vinyl. At the last Austin Record Convention I had a enlightening conversation with a customer about a variety of analog matters. Following on the heels of a discussion of how old quad Lps can be processed with some of todays gear(this was over my head and I can not remember the details) was an interesting discussion of some common Angel Quad LPs and how many of them were made with "Virgin Vinyl". Up to this point the only Virgin Vinyl Releases I knew about were of recent vintage. Apparently the way to tell if your older vinyl is virgin is that when held up against a bright light it will be translucent rather than completely opaque. This discovery was a treat but when I recently checked a Spakers Corner reissue that boasted of being pressed from Virgin Vinyl it failed the test. My question is "Do the current releases that boast of a Virgin formulation use a decidedly different formula than the older releases?"