UPDATE 3/11/2019: I have re-created the file in Fusion 360 and will include the link here. In addition, I have uploaded a newer STL with the similar model (just cleaned it up and added bevels to the corners) for people to download and print.

Link to Fusion model: https://a360.co/2J9zqV0

So, I tried to find a Catan card holder that I liked, and was unable to do so. Instead, I decided to make my own. This is my first ever printable object, and although I am happy with it I am sad to report that there is a small error somewhere in the file that prints an easily removable piece of garbage material. Perhaps someone with more experience can fix this?

In any case, it works splendidly, and if you print two you will have enough to hold the cards for Cities and Knights as well!

To finish it off I stuck little foam rubber bumpers on the bottom to act as feet. Enjoy!

Edit: I have posted the original model files as well, with the hopes that someone can successfully merge the original single line card holder into the double line holder that I tried to make.

UPDATED 3/1/2014
Thanks to HunterGreen here on Thingiverse I have some revised copies now available. I have no 3d printer at the moment, so I can't test them myself. Because of that I am leaving the original files up until I can see that the new ones are better when printed. The new files are named CatanSkew3. Thanks again Huntergreen!