Work aids like folders, guides, and specialized presser feet can be added to sewing machines to improve productivity, quality, and reduce operator fatigue and training time. Folders in particular help fold fabric accurately before sewing for complex seams. They are used for tasks like yoke joining in shirts, hemming pockets, and attaching trims like piping. Different folders exist for different garment types like shirts, jeans, and dresses to automate repetitive folding and stitching tasks. Specialized presser feet also assist with techniques like blind hemming, buttonholes, zippers, and more.