I finally found Krylon Matte 1311, the only brand among the recommended ones that I have been able to locate in Taiwan. I'm making a set of 26 paired with 26, my first R&S DIY. (I realize it's more work, but think of how beautifully certain decks' effects would look when each choice produces a different colored back, alone among whitish cards, each choice a different one from among a gorgeous rainbow of colors!) Doing one with a turquoise deck would be quite pretty, too. All red or all blue can be so...dull sometimes.
I tested a wide vertical stripe of Neo v.2 roughing stick in the center on one pair of junk cards (advertisement cards), with four or five VERY hard strokes to apply it, and found they adhered well (anything less did not adhere enough to be sure to avoid potential flashing), but strong pressure horizontally with the fanning fingers along the center of the cards (an R&S area) could not separate them. However, in the upper left corner of each (a non-R&S area), even light pressure caused them to separate. For that trick, though, having to reach up to the left corner of an R&S pair with the left hand to separate them made it look too much like cards are paired with adhesive; just pressure with the fanning fingers would look more natural, but runs the risk of accidentally separating the adjacent pair and didn't work well when I did a strong vertical stripe. So apparently the direction and area in which you apply them affects their handling and might differ for different tricks. A question for anyone who has made a 26/26 pairing using, specifically, a roughing sticks for you-can-probably-guess-what-trick (or class of trick): did you get better results with e.g. a vertical third stripe application, horizontal third stripe, top and bottom thirds, or a different pattern of application? Has anyone experimented with both for this kind of pairing? (I'll experiment of course; just thought I'd ask for others' experience.)
And a question for anyone using a matte spray is: I assume you do an all over application, rather than attempting to mask off a portion of the card, right? I do realize it will be done in successive light coats until the desired adhesion is achieved. I tried a supposedly matte but actually semi-gloss (grrr!) local brand P.P. spray, as well as a very pricey Mr. Super Clear Matte (which is truly absolutely 100% matte and very good for hiding seams on flap cards). With a single coat (between light and moderate, I'd guess), neither produced any adhesion whatsoever! I'll try again when the Krylon, which is under 1/3 the cost of Mr. Super Clear, arrives.