I was wondering about the envelope size also. Sounds like it's an A7 announcement envelope. My question is though, is the letter printed on 8.5 x 11 inch paper? If so, how is it folded into the envelope? I'm sending out letters as invitations to my son's birthday party, and I can't decide if I want to fold the side of the letter and then fold into 3's or if I want to print on smaller paper that would allow me to fold just once in the middle and place in envelope. Any advice is appreciated.