So, this is a work in progress, but here is what I came up with for some of my own cards (of my dog, Jack):
The jean fabric is very sturdy, but I still added a fairly stiff lining. I plan to sew a divider between the envelopes and the cards, but I think that may be the only alteration. I really like how these came out! I look forward to making them for some loved-ones for Christmas ... but better get going on them!
By the way, for those who are interested, I have placed more goodies in my Etsy Shop.
I hope you are all enjoying the holidays thus far :) Today, we decorate the tree! I'll be sure to post photos soon and hope you will show me your trees as well.