Round perforations in staggered rows (Rv) are shifted by 60°. This is referred to as "standard staggered round perforation. ”This pattern is the one most widely used and combines good stiffness with relatively large free open areas. This type of perforation is often used for sieve plates. Round perforations in straight lines have proven their value in making up retail shop fittings, in particular. The rows of round holes can be offset by 45° to create a diagonal pattern. This variation is used particularly for coffered ceiling and wall panels.