Sewing Tips 63: Pleats
Pleats which are released inches from the seamline, such as those used on the front of pants, begin to work their way loose at the stitching at the end of the pleat when put under stress (a big dinner, perhaps). This can be prevented by decreasing the stitch length 1/2″ from the end of the pleat. Rather than ending the stiching at this point, curve the stitching up and away in a slight curve toward the fold. This additional curve towards the fold helps lock the pleat in place.