For a lot of women, their first experience with a structural shaping garment other than a bra is a corset-back wedding dress — and they quickly learn that a corset is a bit more complicated to wear than a bra. (What, you mean I have to reach in and shift stuff around to get it sitting right?)
Corsets have been around in various forms for hundreds of years. Although body shaping garments have existed as far back as ancient Minoa, the first true corset was invented in the first half of the 16th century when whalebone, horn, and/or reeds were sewn into bodices to give them a rigid shape — giving women's torsos the typically “tubular” silhouette of the Tudors and Elizabethans. By the 19th century, the ideal silhouette was that of an hourglass, and corsets stiffened with steel provided the rigid shapes we know in typical Victorian and Edwardian fashion.
When you compress the average torso in a corset, the person's back skin tends to fold a bit on itself. This is commonly referred to as “back cleavage” or the “Venus Fold.” For some people, it is a natural and normal part of wearing a corset (particularly if they are tightlacing, as it illustrates just how much reduction the person has managed to achieve). Other people don't like how it looks. This is one of those “to each their own” situations.
Corsets were traditionally intended to be a foundation garment — worn over top of an undershirt or chemise, and underneath a bodice, gown, or blouse. The garment under the corset helped keep body oils off of the expensive (and difficult to wash) corset, and both the under and outer garment helped disguise any lumpiness caused by the corset's constriction.
If you want to avoid the Venus Fold, it is a matter of careful fitting… and letting your seamstress or alterationist know to make sure there's not too much compression at the top of the bodice back whilst maintaining enough support at the front. A well-fitted corset should provide waist reduction in the middle, but a smooth line on the hips, and a smooth line up the back when you're standing still.
If you want to minimize your Venus Fold, here are a couple methods you can try:
- Tie the corset more loosely at the top so it's not compressing you and your skin so much
- If you don't want to have your corset looser, have the person who is lacing you in push your skin apart to distribute it more evenly under the lacing
Thing is, if you're going for any kind of reduction, a fold in your back just goes with the territory. You can work with it, but ultimately you gotta learn to love it. Even Dita von Teese, whose corsets are custom-made to fit her like a glove, has some back folding and bumpiness when moving around in a corset: