When I embroidered on cards, I used plain cardstock, cut it to the proper size using a paper cutter and folded them carefully. The office supply store has envelopes, so get them first so that you know what size to make your card.
I loved making my Christmas cards last year and plan to make more this year. Good luck! ~ Nancy
thanks Nancy, it is my idea to get my Christmas cards started early, time just runs away. I tried getting some in Australia without success.