Added to the “official” men’s wardrobe by King Charles II of England on the 7th October 1666, waistcoats obviously have their own “official” rules.
Waistcoats are generally seen as the completion of the suit, adding that extra layer to bring the look together. In this light, waistcoats can be uniform with your jacket and trousers, or be a complimentary item to break up the monotony.
They’re also great items to wear without a jacket for a look that’s smarter than just trousers and a shirt, but more casual than a suit. It’s great for dressing warmly when you still need to move about a lot, as it doesn’t restrict movement as much as a jacket would.
The fit should be snug to your body, with the adjustable waistband helping to cinch the waist. Traditionally the waistcoat will end just at your trouser waistband, though men often feel more comfortable with a longer garment ending above the seat.
Legend has it that Edward VII from the early 1900s (glutton that he was) had to leave his lowest button undone to accommodate his belly. Not wanting to cause a scene in the court, the rest of the gents unbuttoned their last button, and now it’s a thing.
It’s considered excessive to wear a tie bar if your waistcoat is already holding your tie in place, but excessive is not illegal!
It’s generally acceptable to have a flashy waistcoat back, even with an extremely conservative suit. Since the front of the waistcoat is conservative, you’ll only see the back when you remove your jacket, by which time (and by which action) the party is definitely on, so crazy can pass.
– More on Suits –
—Intro, 10 things you should know– Brief History of Suits – The Trouser’s Fit – The Jacket’s Fit – The Waistcoat’s Fit – The Shirt’s Fit — Off the Peg Suits – Made to Measure Suits – Bespoke Suits – Some Suit Mistakes –