Years ago, I bought a paper of an unknown type. It came in in a large sheet (larger than a sheet of Canson art paper) and was available in both a dull metallic silver and a dull metallic blue, with the other side being a darker color with visible lighter clumps of fiber almost like unryu but with finer strands. It was a fairly soft paper untreated (but still very foldable) and slightly heavier than a normal sheet of kami. I got it at an American Ben Franklin craft store in about 2007. What kind of paper was this likely? I still have some of this paper so I can provide a photo of it if needed.
-- Blythe Creamer