I've got two decks with the same design, one blue and one red. Sad to say, I don't have any boxes.
Am I to understand that this is not a Banknote deck? Is there any name for this back design?
Also, my decks, I think, is newer. According to a page I found the "K" can be as late as 1988. When did they stop making this backs?
(I'm sorry if my questions already seems to be answered, but I'm from Sweden and new to the american decks. So I don't quite get the abbreviations.)
This is a "Banknote" deck - one of a few different but similar designs, perhaps five or six in total. They were featured in Aristocrat decks exclusively, as far as I know. The name derives from the intricate and elaborate line work created by the company that originated the design, the American Banknote Company - it's reminiscent of the intaglio print found on many early 20th-century currencies, legal certificates, stocks and bank-issued financial instruments and is still present to some degree in modern US paper money. They briefly entered into the playing card business, selling their playing card assets after only a few years to the Russell Playing Card Company, which eventually was purchased by the US Playing Card Company (USPC). Most versions of the deck bear a calligraphic capital "R" (as in Russell) in the center of the spade on the Ace of Spades, while the most recent reprint from 2009 produced by USPC shows instead a very similar-looking calligraphic "A" (as in Aristocrat).
No one knows the precise reason why Aristocrats were taken out of regular print, but there are a few possible reasons. I do know that USPC places the most marketing support behind its nationally-known and most widely sold brands, Bicycle and Bee. Other brands, especially ones considered to be "regional" (sold only in certain venues or parts of the country) are still in print largely due only to customer demand - and as demand weakens, brands fall by the wayside. A few brands have seen new life as "dollar store" decks, manufactured and sold cheaply (in some cases by third-party companies in China), such as Streamline and Maverick, but others simply become more difficult to find in retail stores that don't specialize in playing cards. Nation-wide chain stores have a tendency to only purchase nationally-recognized brand names in order to simplify the supply chain, though there has been a recent trend toward some degree of regional
The company used to have an exclusive stock used for Aristocrat decks, but they stopped producing this a few years ago - their range of stocks is down to just two, Bicycle and Bee Casino. The Aristocrat brand is still in use and printed, but largely only for casinos to use on their gaming tables. Aristocrat decks were a thick stock similar to Bee Casino grade but were somewhat softer and to some a little easier to shuffle.
In the end, I think it boils down to money. When spending on marketing, USPC can spend a little money on a lot of brands or a lot of money on just a few brands - they saw the latter as the wiser choice. You can still find brands like Aviator, Hoyle and Tally Ho, but they're rarely found in national chain stores and are generally harder to find anywhere but online. So while Bicycle and Bee get the lion's share of the marketing budget, other brands become less popular and less frequently requested, which in some cases leads to sales being so low, it's no longer in the company's financial interests to continue making them. Brands like Aristocrat and Steamboat would fall into that category. Both have had limited-run reprints produced both by USPC and third parties, but are not presently part of the company's standard retail product line.
A good way to know what the company is presently printing and selling is to check out their own website, bicyclecards.com. USPC owns an online retailer, Wingra Direct, that used to operate independently at shopbicyclecards.com, but in the past year or two the company consolidated operations and moved Wingra's retailing operations to their primary consumer portal at bicyclecards.com. On the one hand, it's a wise move to sell directly to the public from the website where they interact with the public the most, but on the other hand, the newly-redesigned website is flashier but less easy to browse than its retail predecessor was. My point is, however, that if you find it on sale there at the regular retail price, it's part of their current output - but if it's not there, or if it is there but at clearance sale prices (typically 99 cents a deck), it's something USPC no longer makes.
Judging from the general condition and the appearance of the court cards, I'd estimate that your "K decks" (assuming both look the same and have the same printing for the Ace of Spades production code) are from 1968 rather than 1988. We'd know better if you had the boxes, but it's a common issue with older decks - the boxes often do not last as long as the cards do. It's definitely not from 2008 - they were out of print I think, and not to be remade until the following year with a new design for the Ace of Spades. If the boxes were intact and it was one of those two years, it would be the deck seal that would be the final factor - a sticker-type USPC deck seal would indicate a 1988 deck while a stamp-type moisture-activated adhesive USPC seal with perforated edges would indicate a 1968 deck. Anything "K deck" older than that would have a USIR (United States Internal Revenue) tax stamp.