PIECES BE WITH YOU-Groovin Piping Trimming Tool. Piping adds sparkle and a professional finish to handbags; pillows; draperies; and much more! This tool was designed to work with 3/16in diameter cording. Learn to sew perfect smooth piping with detailed instructions and diagrams. Place tool over sewn piping and trim seam allowances quickly and accurately to a perfect 1/4in or 1/2 in with a rotary cutter. Constructed of clear acrylic. Designer: Susan K Cleveland.