Synthetic whalebone is a plastic boning made to mimic the qualities of whalebone or baleen, which was historically used in corsets for hundreds of years. Steel boning is made of steel and is commonly used in corsets today. There is a common misconception that steel boning is better than plastic or synthetic whalebone boning for use in corsets. We prefer using synthetic whalebone over steel boning because whalebone is lighter, more flexible, and actually molds to the shape of the body over time as it is warmed by body heat. Steel boning is heavier, stiffer, and will never change shape to adjust to your body over time.