You won't be able to dismiss this by usual means (escape or click button), but you can close it programatically based on user choices or actions.
"the card is very elegant, and the great thing is that you could never have TOO many thank you cards!! the quality is great, although the thermography is kinda faint. I ordered my invitations from another site, and i kinda like those a bit better. but these are still super nice. very elegant and look forward to sending them out"