For women, semi-formal attire is somewhat flexible. Women can wear a dress, pant suit or dress suit. Preferred fabrics for semi-formal attire for women include silk, velvet, rayon, cashmere, high quality polyester brocades, or velour. Usually, anything silky goes. Except for cashmere, a wool business suit is not considered semi-formal attire since it is not dressy enough.
Hem lengths in semi-formal attire dresses vary. Dresses can be cocktail dresses, no more than an inch above the knee, or they can extend to the ankle. Dress suits, for example, a silk suit, usually has a hem length slightly above, at or below the knee. Pants suits, again in silk, polyester, or cashmere, tend to be worn at the ankle. One can also wear dressy tops and tuxedo pants made out of appropriate fabrics and still fit into the semi-formal attire group.
Generally semi-formal attire also means dress heels for women, usually in colors coordinating with one’s outfit. However, a dressy flat or strappy sandal with the appropriate outfit is also considered semi-formal attire. Low, comfy flipflops are not dressy enough to be called semi-formal attire.
How about this (can't snag the photo, so follow the link)? http://www1.macys.com/catalog/product/index.ognc?ID=463254&CategoryID=22120
I am going to a formal wedding in mid September