There are tons of brides on here that have skipped the save-the-dates and went straight to the invites. I don't see anything wrong with it. We send out save-the-dates 1 year before our wedding (October 2009) because we knew we wanted to get married in T&C but we didn't have the actual resort booked until (December) so the STD was very general and just said Turks & Caicos. As for the double envelope issue, its entirely up to you. My mom thought we should have used double envelopes so that the pretty envelope with the Calligraphy and letterpress didn't get ruined with stamps and just the wear and tear of mailing things but I couldn't be bothered. I wanted the outside to be letterpressed and fancy with Calligraphy so that even as it went through the mailing process everyone could tell there was something special inside. And wouldn't you know it one of my friends told her the post man said to her as he was delivering her mail..."Looks like you got invited to a real fancy wedding or party there". Its up to you, some people do it and some don't, it just depends on how you feel about it.