Should be another fun round.
I used Vistaprint for my cards last couple times. Seem to be fine? I don't know how they stand up to postal abuse though.
I usually don't mind the very minor marks on my cards, or slight bent corners, but a lot of my cards during the last couple rounds have been seriously marred. I think the Post Office got a new sorting machine and it very aggressively rips up poor little postcards. One or two cards were so badly damaged I couldn't figure out what the subject of the photo was.
I remember receiving one or two postcards in an envelope (perhaps during RFF Postcard #9?). That definitely protected the card, but here in the US, postage difference between a "letter" and "postcard" adds up. For domestic addresses, it's $0.55 for the envelope, and $0.35 for a postcard. For international addresses, it looks like the Post Office just increased the postcard rate to be the same as the letter rate, so now its $1.15 for envelope or postcard. Interesting. It used to be much cheaper for the international postcard stamp. I wish I had bought more of them last year (during RFF postcard 10)