When you sew canvas or other heavy materials, you may need to fold each edge of the fabric twice to create a double hem. But that also presents a problem: extra-thick corners that are difficult to handle. Fortunately, you can miter the corners to get rid of some bulk. In sewing, mitering is a technique of creating sharp 90-degree angles in the double hem by removing excess layers of fabric. This is an easy method that even beginners can master.
Why is a mitered corner a good idea? On the one hand, mitered corners look more polished and professional than non-mitered corners. Second, they hold hardware like grommets and snaps better than non-mitered corners. See, the non-mitered corners in the double hem are nine layers of fabric—too thick for most hardware components to hold securely around. We recommend three layers as the ideal thickness for mounting hardware.
If you look for instructions on mitering on the Internet, you probably won't find many resources for outdoor applications. That's because mitered corners are widely used in household items such as cloth napkins and quilts made from thin fabrics. But don't worry - thick outdoor fabrics can be mitered. The steps are exactly the same for thick fabrics and thin home decor materials. You can miter corners on boat covers, tarps, and other outdoor items that may require a double hem.
