at least 110# card, probably not above 200# card. 110# is thicker than my playing cards, as an FYI. I've used it for quite shuffleable cards for playtest games.
Once you get past 200# stock, you're into stuff too stiff for comfortable shuffling.
A high rag content is good, as well, as it's more resilient than pure wood-pulp stocks. High clay content is ...
A simple solution if you are willing and able to spend some money:
Buy another copy of the game, a foam paint brush, and a small container of white paint. Using the foam brush you can paint a nice, even, thin coat of white paint over the face of the cards and use a black permanent marker when they dry to write whatever your heart desires!
Crabs Adjust Humidity is a 3rd party expansion pack, they offer packs of just blank cards which are almost identical to the original cards if you don't have enough blank cards in the expansions to write your own cards on. I have ordered about 8 of these now and just keep on expanding my own deck.
The most popular version in the English speaking world is the Rider-Waite Tarot cards. These were published in the early 20th century.
This site has The Pictorial Key to the Tarot that contains B/W images of the Tarot cards (clicking those opens fair quality scans in color). The book and the images predate U.S. copyright laws.
These images here are the ...
There is nothing particularly exclusive to print and play regarding solo play modes. They have the same problems as buy and play games.
There are a great many games that cannot adapt to single player, at least not while still being fundamentally the same game.
I would suggest to your friend that he can work on a different game, perhaps inspired by the ...
Yep, you can download the images from the pictoral key to the tarot here. I'm creating a deck, the Evolutionary Options Tarot which is being released into the creative commons. That means copyright free tarot card images! Have at it, and I'd appreciate any feedback.
Generally, the best solution is to have a very functional design first, with a "pretty version" using the exact same underlying design, but with full color pretty images, including both in the package. The simple functional version will often be the trial - it needs to be low ink, and preferably grayscale.
If the underlying design isn't functional, the game ...
I created templates for printing on the 'Spare cards' that come with the expansion packs.
I then bought Avery Crystal Clear labels (L7784)and used a laser printer to print them out. I cut them to size then applied them to the blanks and they look and feel almost identical to the Originals.
Expansion packs 1-4 each include blank cards - 8 white cards and 4 black cards. The Bigger Blacker Box expansion (and box) contains 50 blank cards (10 black and 40 white). These blanks printed using the exact same process as all the other CAH cards, so they're virtually indistinguishable from the official cards. With a blank card, you just write on it with a ...
You could always buy a pack of blank cards and then use Moo.com to create custom stickers to stick on the blank side. It would be virtually impossible to tell the difference unless you really disturb your cards
A cheaper suggestion is this: buy a set of card sleeves with one opaque face, print your cards and sleeve both your set and the original set. No one will know what they might draw. There are many options being sold in Amazon.com and in many other game stores.
You may want to know more about the quality of those sleeves prior to buying.
There's a website for making your own, generating a PDF, sharing, and printing your own cards. Unaffiliated with CAH or Apples to Apples, but quite similar and easier than hand-writing or editing a PDF.