Nylon VS Spandex
Construction - Corset vs Waist Cincher
Steel boned corsets are constructed from a strong, yet flexible fabric (cotton / satin / leather/mesh) that is reinforced with steel boning (flexible steel rods) to give the corset great strength for pulling in your waist and accentuating the curve of your hips and bustline. Most waist cinchers are made from a combination of nylon and latex or Spandex, some with plastic or steel boning. If you carry your weight in your tummy, they can help give you more of a waistline, but not the same hourglass curves as a steel boned corset.
How They are Fastened & Tightened
Corsets help you to re-shape your body over time (like braces for your teeth) because they can be tightened using the laces, whereas a waist cincher (contrary to the name) can not because the closure on a trainer has only eyes and hooks, not laces. You will need to purchase a new cincher if you lose or gain too much weight because it can only be loosened or tightened minimally depending on how many rows of hooks and eyes the cincher has. Typically corsets are tightened by fastening the front busk (a piece of corset hardware consisting of two steel stays, one with metal loops, the other with metal 'pins') and then cinching the corset by tightening the laces in the back.
Styles
Corsets are made to fit around your midsection and can be either an “overbust” or an “underbust, ” and depending on your style, can be worn . Corsets come in a number of styles that have less and more extreme curves, and that fit a variety of different body types.
(Related: See Corsets Styles & Buyer's Guide.)
Waist cinchers / trainers come in a variety of colors, patterns, and prints (some with fun sayings). You can also find cinchers that offer a variety of different coverages, from the simple waist trainer, to thong body suits, versions with straps, and even body briefs.