so ink saturation is a big factor in how quickly a deck wears out. that being said, black cards seem to be quite popular and more people seem to be designing them. So do you think a black stock would be economic for the USPCC to use? like have an actual black sheet that isnt ink. like the monarch boxes. (think construction paper or something along those lines) just a thought
Ink saturation has more to do with the softness of the card. Depending on how the card is used, that can affect lifespan differently.
In point of fact, if you're talking about "black cards" in the sense of decks like Black Tiger and Black Ghost, there's more of a trend away from those kinds of decks. Many of the more recent releases from the various well-known companies are white-bordered decks with backs in various colors. Artifice v.2, Infinity, LTD, Monarchs, much of what Dan and Dave have put out, NOC decks - these are all "non-black" decks with white borders. One definite trend would be towards a cleaner and more elegant look, which is why some aren't even customizing the faces, such as Zenneth Kok's new Bee deck. He specifically wanted something for his own performances that would allow the audience to recognize the cards and not be distracted by them. A custom-faced deck like Sentinels would have a totally different feel to it, depending on the performance and the performer.
The biggest reason that black decks started falling out of favor, in my opinion, has nothing to do with ink saturation and everything to do with chipped edges. Every card chips at the edges with use, unless they're handled with kid gloves and never riffled. On white decks, it's not much of an issue because the paper beneath is white. But for black decks, it's a totally different story.
I've spoken with others about the idea of using a black paper in the past. The problem then becomes printing on the face in colors and white - you'd have to come up with some kind of silk-screen process, literally sticking the ink to the card's surface. It would very difficult getting the cards to be completely flat at that point - and sensitive fingers would be able to read the inks by touch if they weren't flat.
Rajas Paranjpe at Brahman Playing Cards has mentioned that he can do a similar process using black PVC for the card stock. But I don't think he's actually tried it yet for a client. I have a sample deck of his in the black PVC - it has a certain appeal to it if you're a fan of black decks.