Definition
Piping is a narrow, rounded trim made of a cord wrapped in a bias strip, sewn into a seam so that a fine raised line shows along the edge.
Piping outlines a seam with a contrasting or matching line. You see it on cushions, bag edges, yokes, pockets, collars and princess seams, and in upholstery, where it is often called welting.
To make it, fold a bias strip around a filler cord, sold in sizes from about 2 to 10 mm (1/16 to 3/8 in), and stitch close to the cord with a zipper foot or piping foot. The strip's width is the cord's circumference plus two seam allowances: for a 3 mm cord and 1.5 cm (5/8 in) allowances, cut about 4 cm (1 1/2 in). Flat piping, without cord, is a folded bias strip inserted the same way.
To insert it:
- Baste the piping to the right side of one piece, with its stitching on the seam line and the raw edges together.
- Clip the piping's allowance at curves and corners so it bends.
- Place the second piece on top, right sides together, turn the work so the basting line is visible, and sew slightly inside it, closer to the cord, so the first stitching is hidden.
Where the ends meet, overlap them and curve them off into the seam allowance, or open the strip and join the ends. Prewash the cord if the item will be washed.
A cushion cover is a good first piping project. Compare with bias binding.