Belt loops for jeans can be difficult to sew onto the garment since they are thick and narrow. The machine’s presser foot must climb or descend as you stitch close to the edges, resulting in uneven stitches or snarled thread. Although there are commercial jigs available to lift the presser foot and keep it level, you can create a simple jig that is exactly the right size and thickness for the garment you’re sewing. The jig is made of fabric folded to match the belt-loop thickness and has a notch that fits around the end of the belt loop. It provides you with a flat stitching surface around the belt loop, so there are no humps for the presser foot to jump.

Make a test loop with your fabric to determine the best loop length: The fabric’s stiffness and thickness may call for longer extensions so you can fold the ends under easily. The belt loop in the example on the facing page was made by folding the fabric in thirds and stitching along the edges. If you stitch close to the edges, you may want to stitch down the middle, as well, to make sure the fabric’s raw edge is caught in the stitching on the wrong side. The belt loop was lengthened to make an allowance of 3/8 inch at each end. This makes it easier to fold and keep the ends under when you’re sewing. If you sew pants often, you might want to make several jigs in different thicknesses and keep them handy for attaching belt loops.

Make a stitching jig 

Quilt folded fabric layers to make a pad the exact thickness of the belt loops.

1. Fold the jig fabric. Cut a strip of the garment’s fabric 3-1⁄2 inches wide and 18…