This is a very simple and flexible pattern for a quick to knit pouch for cards (or any rectangular object).

Gauge is not important as you will be measuring the piece against your deck. While I have listed the needle size and yarn weight I used, these are really only suggestions, and the pattern can be adapted trivially to most needle sizes and yarn weights from fingering up to aran by simply using the recommended needle size for that weight. Obviously this will effect the thickness of your bag, but that’s about it.

You will need circulars or DPNs for most of the bag.