a black cummerbund or low-cut evening waistcoat is the most traditional way to cover the waist (with a single-breasted jacket)
a recent trend is to leave the waist uncovered
Black Tie Waistcoats
This black-tie waistcoat is a backless model, and features four polished buttons, a matte wool body with self-faced lapels, and two jetted pockets.
The classic evening waistcoat is a rare find these days as it has been virtually replaced by models that are cut higher, lack lapels and are exclusively single-breasted. In other words, the new formal waistcoat is essentially just a shiny version of a regular suit vest.
Black deep cut grosgrain silk vest with rounded corners at the bottom and three buttons – British 1930s style
Formal waistcoats are meant to showcase the formal shirt’s decorated bosom which means they should barely extend beyond the dinner jacket’s lapels. This low cut also preserves the physique-enhancing deep V created by the contrast of white shirt against the closed black jacket. Consequently, the tall height of a suit-style vest is inappropriate for a traditional single-button jacket. It could, however, be used to improve the formality of a two-button dinner jacket the same way a regular vest adds authority to a two-piece business suit. Just be sure it is cut to a medium height so as not to interfere with the jacket’s V opening.
Waistcoats commonly marketed with black-tie ensembles today are cut incorrectly, resembling styles worn with business suits.
Modern waistcoats are constructed in the full-back style, depriving the wearer of the comfort of a backless model. Young men will use this deficiency as an excuse to strip off their jackets at the first possible opportunity, often thinking that the silk backing qualifies their vest as a stylish substitute for their jacket. It doesn’t.
Even though it is ok to leave the bottom button on a waistcoat undone, evening waistcoats are traditionally buttoned all the way. Except for waistcoats with more than four buttons, those can have the bottom button undone.
Avoid patterned waistcoats or vest that are closing to high up – evening waistcoats are always cut deep
Modern waistcoat separates are usually finished entirely in satin or, less commonly, grosgrain and should match the finish of the accompanying dinner jacket’s lapels. Cashmere or velvet is also an appropriately luxurious choice. If buying a separate waistcoat constructed of wool keep in mind that the fabric will not be identical to the wool of your tuxedo and might appear mismatched.
Color and Pattern
Colored and patterned vests offer much more latitude in choice of fabric as they don’t have to match the dinner suit’s materials. However, these variations can be a slippery slope to sophomoric prom wear so be sure to consult the Contemporary Alternatives page before heading in this direction.
The clownish 1980s practice of matching brightly colored cummerbunds with identical bow ties may largely explain why the formal sash has significantly declined in popularity in recent years. It has also been facing increasing competition from the vogue for finished waistbands on formal trousers. Regardless, it remains a perfectly stylish and correct accessory providing that any modern trends in color or pattern stick to the guidelines found in Contemporary Alternatives.
Ryan Gosling in a striped turndown collar tuxedo shirt wiht 4 studs but without a cummerbund in 2007
Today many men are choosing trousers with a satin finished waistband in lieu of either type of traditional waist covering. Despite the fact that an exposed waistband is still regarded by many as a formal faux pas, this option was given a significant boost in credibility in 2006 when Daniel Craig flashed it on the poster for the hugely popular James Bond film Casino Royale. However, those men intent on imitating Mr. Craig’s edgy appearance at their next black-tie gala should make sure to separate fact from fiction:
Craig’s exposed waist is part of a deliberate dressed-down look for the purposes of the poster. Unless you plan to also copy his unbuttoned shirt, undone tie (and unholstered handgun) you should take your cue from the film itself wherein 007 always buttons his jacket when standing thus keeping his waistband covered.
Craig’s dinner suit was personally made for him by a master tailor and his stomach is as flat as a washboard. If you can’t duplicate these factors then don’t expect to duplicate his formal waistline.
A black waist covering extends the leg line thus creating the illusion of longer legs. Omitting this covering creates the opposite effect.
The absence of a waist covering reduces the outfit’s formality, particularly if wearing a long tie and a suit-like dinner jacket.
Even with the jacket closed the bottom of your shirt will still become exposed anytime you place your hands in your trouser pockets because this action naturally spreads apart the jacket fronts. (This shortcoming is easily overlooked by men who are used to having their tie cover up their navel when wearing regular suits.)
George Clooney in notched lapel tuxedo without cummerbund
Finally, would-be imitators should also keep in mind that traditional formal shirts will not work with this look as their stud holes do not extend all the way down to the waist. Consequently, the working button intended to be hidden behind a cummerbund or waistcoat will instead be very much exposed.
Contemporary Tuxedo and Black Tie Evening Vests
Learn all about contemporary Black Tie options for waistcoats and cummerbunds and what mistakes to avoid so you don't end up looking like a peasant.