and are applied in a special way so that they disappear into a seam. When properly applied, neither the stitching nor the zipper teeth or coil is visible on the outside of the garment. Invisible zippers are used principally in skirts and dresses but they can go, in general, wherever a conventional zipper might be used, except in a trouser placket. Some manufacturers sell special zipper feet designed for application of their products. Some invisible zipper sizes are aggregates: e.g., 7”-9” is one size.