This is the only slip I've ever seen that has a zipper. A 9'' metal underarm zipper is on the right side, the opposite of where zippers on dresses usually are. There's a slight gather of fabric at the neckline. The narrow straps are adjustable. Darts give it shape. The waist is slightly dropped. Lace is at the hem. Perhaps this was worn under a wedding dress. The white is slightly off, not snowy white. How daring it would be worn over a slip dress or unitard. It's in very good condition.
Wispy White Underslip