Make sure it's an evening wedding, then. There's nothing more gauche, IMO, than a daytime wedding calling for black tie. I've been to a few recently, and the grouchy, SF-influenced curmudgeon in me wants to assert that tuxes before 6pm are in almost equally poor taste as daywear after 6.
W/r/t Manton's inventory, I want to second the motion that tweed be struck from the list for those who just can't justify it in their climates. I live in LA proper, and I can get away with true, fully lined, heavyweight tweed maybe once a year. The season for it is maybe a half month out of twelve, and with the way things are going, the window be shrunk eventually to about 3 or 4 days. We do have some cool nights every now and then, but tweed is such an oddity here that the occasion to wear it would seldom present itself, even if the weather momentarily permitted.
I will add tweed to my "Things I Can Get Away With When I Become a Bestselling Novelist" list, alongside casual bowties, detachable-collared shirts, and spectators.
I do own a few sportcoats that I would call pseudo-tweed, such as a linen jacket in outsized herringbone pattern, and a beautiful brown lightweight "tweed" by Partenopea that is sort of the fairweather, Italian approximation of the real deal. But I would boil alive in genuine Harris.
Edited by Jackie Treehorn - 8/1/12 at 3:38pm