Pinch your waist in by 3"

Reducing your waist measurement by 3 inches is quite a challenge, so only the heaviest duty waist cinchers and corsets will do the job. You will probably have to work up to the 3 inch reduction by trying these items on a slightly looser setting first.  The steel boned corsets do have the capability to reduce your waist by 4" but this is highly dependent on your physique and current shape - so I would not be confident in guaranteeing this would be possible for everyone.