I'm also planning a 1940's wedding and have gotten alot of splendid ideas just surfing the web. But first I did some research on the era. It was very Hollywood and glamour. So my gown is a replica of a starlet's day gown, very liquid sleek, sophisticated, sexy with sholder pads. The veil is very short attached to to a splendid 40's hat that lays low down near an eye, at an angle. Calla lilies were the accepted wedding flower. My centerpieces are really neat (e-mail me and I'll send you a picture). Favors are miniature calla lily candles. I'm also having a crescent moon fashioned to use as a backdrop for pictures (remember seeing those starlets sitting on a half moon looking so sad). I'll be more than happy to send anyone pictures if interested.
Just an idea for people that put in a lot of work on themed weddingd. There is a genre of photography that focusses on the golden era of Hollywood (sadly, I have not been trained in it YET.) It usually involves a different kind of lighting and posing that can replicate the photography of the time. It would be very cool to have a photographer that can keep in your theme and have your wedding pictures reflect what you have worked so hard to accomplish. :)
If you do not have a photographer yet, try posting a listing for a photographer that can do Golden Age of Hollywood photos or perhaps someone that specializes in black and white photography and color tinting.
