I never noticed this thread until tonight, but having just read through it I feel like everybody missed out on mentioning something to the OP that is near and dear to the heart of most poker players here at PCF. That is the concept of a "Card Setup" being defined as 2 decks of playing cards - each deck with a different colored back - packaged together in one case (like the Copag example below). This is vitally important because when I looked at the OP's Kickstarter campaign it looked like all of their current products consist of just a single deck of cards housed in a tuck box. And those work totally fine for people interested in magic, cardistry, playing solitaire, etc. But people hosting a poker game want two decks in different colors so that you can alternate having a person deal one deck while another person is shuffling the second deck.
Along those same lines, I think the question the OP has to ask themselves is if they are interested in making "the best playing cards" or making "the best cards for playing poker." And despite sounding similar those are not actually the same thing at all.
Designing "the best playing cards" would likely result in a fancy paper tuck box containing a single deck of poker sized cards on some crushed paper stock such as Cartamundi's True Linen B9 Slimline stock, with a standard index, gilded card edges, a full-bleed back, probably some use of cold foil, and an emphasis on truly gorgeous artwork. Based upon what I saw on the OP's Kickstarter page, this seems to be what they are aiming for. Which is totally fine of course, and I certainly wish them the best of luck with their project. But the thing is that we see tons and tons of Kickstarter campaigns coming out with cards designed for this market, plus there are all of the "artisan card makers" such as Kings Wild, Theory11, Ellusionist, Stockholm17, Black Ink Branded, Card Mafia, Montenzi, etc. So this seems like a pretty crowded arena, and it doesn't really apply to PCF members / poker players very much anyway.
Designing "the best cards for playing poker" however, would likely result in a plastic box containing two different-colored decks of bridge sized cards on some nice plastic/PVC stock such as Dal Negro or Fournier, with a large (AKA blackjack) index or an extra-large (AKA jumbo) index, non-gilded card edges, a bordered back, probably 4 colors for the 4 different suits, and an emphasis on readability from across a large poker table. And yet interestingly, I haven't seen any Kickstarter campaigns designing cards like that, nor do we see any of those "artisan card makers" really competing in this space. In fact, I think the closest we can even get to seeing "startups" in the poker card arena might be Faded Spade, Desjgn, and Broken Arrow. So it seems like there could definitely be some opportunities to truly innovate within the poker card market, just as long as one "plays their cards right" (sorry I couldn't resist LOL).