The PSFS Building has been hailed as the first truly modern skyscraper. It was not clad with the heavy stone of its skyscraper ancestors, but had membrane-like walls of glass and metal. The windows were set in ribbon-like horizontal strips, not square boxes punched in the side of brick cladding. The form of the building showed a clear distinction of parts, and the tower utilized the powers of steel frame construction to cantilever the tower out over the base. There would not be another skyscraper that followed the tenets of Modern architecture so closely until after World War II.