The vest is the forgotten part of a suit, one that fell out of style during World War II when people could not afford them. Businessmen wear the suit jacket and pants without the vest because the vest is considered too formal or passe. The vest, however, is making a comeback, and it adds a formal element to the suit. A vest worn without a jacket brings style and flair to any man's work and casual wardrobe.
Tailor the suit vest to fit properly, just as you would with the rest of a three-piece suit. The vest should cover the top waistband of the trousers and rest directly above the jacket lapels. A well-tailored vest makes the chest look bigger and the waist look smaller. Suit vests come with a back adjuster, allowing you to adjust the vest to fit your size and shape. To find a comfortable fit, move the back adjuster to a position that works for you. Put on the vest and sit down. If the vest feels uncomfortable, readjust it to get the perfect fit.
Buy the suit vest as a part of a three-piece suit to be sure all three pieces match perfectly and present a businesslike appearance. Do not attempt to add a separate vest to a two-piece suit, creating a noticeable difference in color and fabric. This cheapens the formal look. Wear a mismatched vest only when dressing casually, and try to find a vest that complements the pants being paired with it.
Wear the vest with the entire suit, a dress shirt and a tie for a formal, business-appropriate ensemble. Use this look to impress a client or for an important presentation to convey the image of a confident businessman. For a night out or a business casual work environment, remove the jacket and roll up the sleeves of the dress shirt. This look is still dressy, but conveys a more laid-back and casual attitude. When wearing a six-button vest, formal wear etiquette allows for the bottom button to remain unbuttoned for comfort when sitting.
Wearing a suit vest as a separate piece allows for more options and gives the vest a casual look. Mix the vest with dark wash jeans or khaki pants. Wear a T-shirt or button-down shirt underneath the vest. Try wearing plaid or striped patterns to create a signature look. Add a bow tie or regular tie in a unique color or pattern under the vest. Pair the vest with leather shoes or boots.