Thematic Action Decks are very popular within the Savage Worlds community, and several publishers offer custom decks tailored to their own settings. There are even decks with specialized features, such as the Mutation Deck by Just Insert Imagination, or the Hellfrost Action Deck by Triple Ace Games.
The new Chase rules in the upcoming Savage Worlds Adventurer's Edition also require a second Action Deck, and it wouldn't surprise me to see publishers introducing new decks with special features for Chases. Pinnacle has released a preview of the Chase rules here.
While it's already possible to create your own Action Decks (like I did with my Countdown Decks), once the Savage Worlds Adventurer's Guild (SWAG) goes live, we'll also be able to publish decks that explicitly reference the Savage Worlds system. This will include Adventure Decks, equipment cards, NPC cards, decks with special rules (like the aforementioned Mutation Deck), and so on.
OneBookShelf (OBS) provide a lot of information about printing your own cards, including specs, tutorials, and templates for InDesign and Scribus. Take a look here for the details, and pay particular attention to this page.
As well as poker cards, you can also print (smaller) bridge cards and (larger) tarot cards. The same approach can be used for printing tiles and poster maps.
Designing your Cards
You can use image-editing software like Photoshop or GIMP to design the cards themselves. If your cards have text, some people will recommend adding that with your desktop publishing program (i.e., Scribus or InDesign) -- however I personally like to create the entire card as a single image, as this makes it much easier to offer print-and-play and Virtual TableTop (VTT) versions of my cards as well. It also means I can use a standard Scribus template to rapidly generate a new deck.
Usually, playing cards only have portrait illustrations on the face cards (king, queen, and jack) and jokers. Some Savage Worlds rules explicitly reference "face cards," so it may also make it easier for the players if you follow this standard. On the other hand, if you can afford sufficient artwork, some players really enjoy having a unique illustration on every card!
The artwork is probably going to be your main expense when producing a deck of illustrated cards. If you already have plenty of artwork for your setting book, then you can reuse it for your cards -- but if you have to commission a full set of artwork just for the deck, it could take hundreds of sales to recoup your expenses, and the market for custom decks simply isn't that big. Even if you're buying stock art, it can be difficult to break even, let alone make a profit.
For my Countdeck Decks, I used artwork I'd already purchased for the Saga of the Goblin Horde and Monster decks, and bought (and cleaned up and combined) some stock art for the Galactic deck. I used a free font for the ranks and suits, and Game-icons.net for the special symbols. It was a lot more work than I'd expected, but it was an interesting learning experience, and I was pleased with the results.
Of course, the decks don't need to be individually illustrated, particularly if they're primarily text-based. The Mutation Deck is a good example of this approach -- while it has a nice visual design, its main value lies in its functionality (the mutations).
As of December, premium poker cards cost 9 cents each, so a standard 54-card deck of playing cards (plus a title card) will cost $4.95 to print. You can reduce this cost by ordering in bulk, but you will need to order at least 5,000 cards (they don't all need to be the same deck, so if you offer multiple decks you could order a mixture).
When it comes to deck cases, you have two options. The first is a clear plastic case, which comes in "standard" and "large" sizes (holding up to 70 and 120 cards respectively). The second option is a tuck box, which can be designed for 54, 72, 90 or 120 cards (or 80 cards for tarot decks). You cannot offer both deck cases for the same product.
If you offer a clear case, the customer can choose to add it when they purchase your deck. This will cost them an extra $1 (regardless of deck size). Sometimes they'll get the large case, even if your deck is regular sized -- I'm not sure why, but I'm guessing it depends on what the supplier has in stock.
If you offer a tuck box, you will have to design it yourself, although once again OBS offer templates. As of December, the tuck box adds $2.25 (for a 54 card deck) or $2.50 (for all other sizes) to your production costs and is automatically included in the order. The tick boxes are quite a snug fit, and it can be a bit of a squeeze if you decide to offer 4 jokers instead of 2.
It should also be noted that if you offer your decks in a bundle, the customer cannot currently add plastic cases. They can purchase them separately (as part of the same order), but then the cards won't be delivered inside the case, and thus the shipping cost will be higher. OBS have said they hope to address this in the future.
OBS only offer card printing services in the US, and the shipping costs to Europe are brutal (this is the same for everything, it's not specific to OBS). However you need to order a proof before you start selling your cards, so it's a necessary expense.
This isn't a problem for publishers living in the US, of course. But for me (in Germany), the postage was $14.55 for 1 deck, $23.58 for 2-6 decks, then went up to $35.21 for 7 decks (I stopped checking after that). That's part of the reason why I decided to create multiple Countdown Decks -- it meant I could order two proofs at once, and add a few goblin decks to give to friends and family!
Unfortunately, while multiple decks can reduce the postage costs, they also increase the chance of your cards getting stuck in customs (adding further delays and expenses). Gah! OBS have said they're looking into a European printer for cards, so I really hope they find one soon!
Selling your Deck
OBS will keep 30-35% of any profit you make on top of the production costs (depending on whether you have an exclusive or non-exclusive deal with them). You will also need to recoup the cost of your artwork, as well as the printing and postage of your proof prints and/or any promotional giveaways for reviewers. A little breathing room in the price will also give you the opportunity to hold sales, or include discounted decks in bundles.
When I looked at other Action Decks on DriveThruRPG, I noticed that standard thematic playing decks tended to sell for around $10, while those with special features often sold for $15. In the end, I settled on a $12 price tag, or $9 each if you buy the bundle.
I was also quite surprised to see how popular the plug-and-play version is. That's a PDF designed for home printing. I sell those for $3 each (or include them for free if people buy the physical deck).