When attending a black tie event, women are expected to wear a formal dress. The length of the dress can vary between short and floor length.
"Emily Post's Etiquette" defines black tie attire for women as "formal evening dress or short, dressy cocktail dress."
When determining what to wear, read the event's invitation carefully, and note if there are any additional dress code requirements, such as a request to avoid a certain color or a request for all women attending to wear a particular length of dress. Begin with the dress, then move to the shoes and accessories, such as the jewelry and handbag. Unless dancing is to be an event of the evening, choose a pair of formal heels; open-toe heels are acceptable. In terms of jewelry, if it is appropriate for a cocktail party, it can be worn to a black tie event. Finally, for a handbag, an evening clutch or minaudiere that is made of silk, beaded, velvet, brocade or satin is most appropriate. Furs are also commonly seen at black tie events.
If any doubts exist over the host or hostess' expectations regarding the black tie dress code, invitees can reach out to that person to eliminate those doubts.