I had a problem today when I went to mail my 2nd round robin to Australia. Last week I mailed my initial round in a brown manila envelope and it cost me $2.08. I purchased a cardboard envelope to send my next round in and when I went to mail my 2nd round envelope today it was over $5 and because it was a cardboard envelope instead of a paper envelope, I also had to fill out a customs tag to attach to it. Well, I learned my lesson. It will be a paper envelope from now on for sure!