That's cuz the really thin ones were Dynaflex, not Dynagroove. They're both RCA and it gets confusing.
05-21-07: 4yanx
Funny the RCA Dynagrooves. I recently obtained a sealed copy of a Japanese quadraphonic LP that had the Dynagroove label but it was pressed on 180gr vinyl. It seemed SO odd to see that label and to hold the record on each edge WITHOUT it sagging in the middle! :0)
Common
I recently bought three new Classic pressings, all 200g titles: Norah Jones; Diana Krall; and Tull's Aqualung. All were defective. In examining the vinyl I noticed a threadlike discoloration which was literally stitched into the vinyl. When the stylus runs over this, both channels distort rendering the passage unlistenable. Clearly, Classic is not using virgin vinyl and some form of foreign matter is being added. Dare I consider this might be the labels from old LPs recycled? Anyone else notice this or have similar experience?