Silhouette Levels, Orchard Corset's exclusive system for measuring the degree of "curve" in our corsets, has revolutionized shopping for "off the rack" corsets. Using a matrix of ratios (waist-bust and waist-hip) we can help you determine which corsets are best suited for your figure and corset demands. Level 3 corsets offer extreme curves with a 10+ inch hip-waist ratio and a 8+ inch waist-bust ratio (used for overbust corsets). These ratios are determined by measuring your natural waist (smallest part of your waist) and then your hip and bust measurements. The difference is the ratio. For example, if you have a 26 inch waist and a 37 inch hip, your waist-hip ratio is 11.