Black tie attire for women typically consists of elegant gowns that would be worn to a ball or wedding. Black tie events require very formal dress for men and women.
If a woman has been invited to a black tie affair and a formal gown is not on hand, she can opt for a silk blouse paired with a full skirt. While having black in the outfit is appropriate, it is not required. Women should opt for darker or subtle shades. Cocktail dresses or other dress that are revealing or low-cut are not appropriate for these events. Men typically wear tuxedos.