A double-fold hem is a sewing technique used to finish the edges of fabric. It involves folding the raw edge of the fabric twice, which creates a clean and polished look. This method helps prevent fraying and adds durability to the garment or textile item. Typically, double-fold hems are used in various sewing projects, including garments like skirts and pants, as well as home decor items such as curtains. The process can be done by hand or with a sewing machine, making it a versatile choice for both beginners and experienced sewers.