If you're looking for substitutes for the Presentation matte, keep in mind that it has OBAs in it; it's "bright" (more bluish). The Premier Art papers noted and the Epson Hot Press natural are OBA free and will look warmer. The "Bright" version of Epson Hot Press might be one to try.
The "brighter," "whiter" side is usually the printing side. If you touch the surface with the end or your tong, it'll stick to the inkjet coated side, but not the base paper, uncoated side.
Paul
On Mon, May 2, 2016 at 11:18 AM, andrey@... [DigitalBlackandWhiteThePrint] <DigitalBlackandWhiteThePrint@yahoogroups.com>; wrote:
I'm curious: which side of UPPPM do you guys print on? I use the side that looks whiter to me, but it may be slightly rougher in texture. Never sure which is the right side with this paper.