Men’s traditional 1940s formal wear choices were: white tie (formal), black tie (semi formal) .
1. White tie formal wear is mostly the same today as it was in the 1940s.
Black tailcoat with satin lapels in a rounded shawl collar shape or wide pointed peak lapels
White button down or stiff front wingtip dress shirts (or pleats)
Suspenders (white is best)
White silk bow tie
White single-breasted dress vest with long square lapels
High waist, pleated tuxedo pants with a satin stripe down the outer leg
Patent leather tuxedo shoes or plain polished leather Oxfords
Black socks (silk or wool)
White pocket square
Colorful silk flower boutineer
Black silk top hat
Optional, dark blue or grey overcoat with satin lapels and dress cane
2. Black tie formal wear was increasingly popular from the 1920s onward. It could be worn wherever formal wear was requested with a few different looks to choose from.
Dinner jacket with wide silk or satin peak lapels and a nipped in waist. The drape was long, to mid thigh. Single or double breasted jackets were worn as well as the shawl collar jacket. Black or midnight blue with black satin lapels.
White stiff front starched shirt with an extra large wingtip collar
Black shawl collar dress vest (backless is OK)
Black pleated pants with stain stripe or braid on outer legs, very high waist
Black or dark blue “club” bow tie (not a fat butterfly shape or skinny ribbon)
White pocket square (the twin peaks was the best fold)
Optional, black shirt studs and cuff links
Optional, white woven knit or silk shawl (muffler) with monogram initials
Optional, black homburg hat