These jumbo clips open wide for multiple layers and won't damage or distort fabric. They are a perfect alternative to pins, especially when working with vinyl's, piles, and heavy weight fabrics. The bottom plate of the clip features seam allowance markings and slides easily on the sewing machine deck. The rounded nose allows the foot of your machine to ride along the front for neat stitching. These are a wonderful time saver. They make sewing and crafting more enjoyable while contributing to a finer finished product.