Dunno...but I did hear that there will be a new sanded solid Power Groove released sometime this year. Evidently the old colors weren't conducive to sales or some such.
I also have a sanded PG, but I put a couple coats of the Brunswick polish on it. I concur with Dan's observation--very smooth reaction, much more so than the pearl PGs.
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...formerly "The Curse of Dusty," and "Poöter Boöf" before that...