3M Wetordry paper sheet 431Q features extra fast cutting silicon carbide on a strong C-weight, waterproof paper backing to provide superior finishing for both wet and dry applications on a variety of substrates, including paint primer, gel coat, metal and wood. Used dry or with water, 3M Wetordry paper sheets enable the user to rinse areas of the workpiece and the sheet during use to prevent dust and debris from clogging the points of the abrasive and reduce air-borne dust, while producing a faster cut at the same time. These versatile sheets are ideal on surfaces that tend to generate a lot of dust, such as paint and primer; and can also be used dry for finishing metal and gel coats. In the marine industry they are used for sanding old finishes, fine featheredging and surface work. The standard 9 x 11 in sheets can be cut to size for the application. Silicon carbide is a very hard mineral characterized by sharp points that fracture easily, resulting in freshly exposed sharp edges that cut extra fast and produce a smooth, professional looking finish. Silicon carbide products are commonly used for low-pressure applications such as paint prep and finishing on wood and metal. While the mineral has a shorter life than aluminum oxide, it produces a superior finish. Our 3M Wetordry products are backed with our proprietary waterproof paper backing that supports both wet and dry applications. Lighter weight than cloth and smooth rather than textured, paper backing is preferable for lighter applications such as finishing and paint prep. At the same time, many such applications produce a significant amount of dust, clogging the abrasive points and creating an inferior work environment. These effects can be minimized by sanding with water to rinse dust away from the workpiece and the abrasive surface.