Piping cord is one of those quiet components that decides whether a finished cushion or sofa looks handmade in the good sense or handmade in the rough sense. It is the soft round core that sits inside a strip of folded fabric to create piping — the raised, corded trim you see running along seat cushions, chair backs, bag edges, and tailored jackets. Get the cord right and the seam looks defined and professional. Get it wrong and the edge goes flat, lumpy, or ripples after the first wash.
We twist piping cord from 2 mm to 8 mm with a deliberately soft twist, as the bare filler core rather than covered welting; see the piping cord page.
As a cordage manufacturer, we make piping cord by the reel for upholsterers, cushion makers, and garment units, so this guide is written from the workbench, not the catalogue.
What is piping cord?
Piping cord is a flexible cord made to be covered, not seen. Its whole job is to give piping a consistent, rounded profile. Traditional piping cord is cotton — soft enough to fold fabric around cleanly, with enough body to hold a round shape along a seam. It is usually a twisted or cabled construction so it stays supple and bends around corners without kinking.
People sometimes confuse it with cord meant to be seen on its own, like drawstring or decorative rope. Piping cord is different: it is chosen for how it behaves under fabric. That means an even diameter along the length, a smooth surface so it doesn't telegraph bumps through thin fabric, and enough flexibility to curve tightly at cushion corners.
A quick note on shrinkage: natural cotton cord can shrink slightly the first time it gets wet. If the finished item will be washed, either pre-shrink the cord and cover fabric or plan for it. For upholstery that stays dry, this is rarely an issue.
Piping cord sizes and which to choose
Cord is sold by diameter. The right size depends on the fabric weight and the look you want — a fine dressmaking pipe needs a thin cord, while a chunky sofa seat wants something substantial. As a rough guide:
| Approx. diameter | Typical use | Feel |
|---|---|---|
| 2–3 mm | Dressmaking, fine cushions, lightweight fabrics | Delicate, low-profile edge |
| 4–5 mm | Scatter cushions, curtains, bag trims | Balanced, all-round choice |
| 6–8 mm | Seat cushions, headboards, medium upholstery | Defined, structured line |
| 9–12 mm | Sofas, heavy upholstery, bold decorative piping | Chunky, statement edge |
If you are unsure, match the cord to the fabric: heavier fabric can carry a larger cord, while thin fabric looks best over a smaller one. When you are buying for a specific project, our piping cord product page lists the diameters we hold, and you can always request a quote for a size or quantity that suits your run.
How to use piping cord: step by step
Making your own piping is straightforward once you have the cord and a strip of fabric.
- Cut bias strips. Cut fabric at 45 degrees to the weave. Bias strips stretch slightly, which lets the piping curve around corners without puckering. Width = the fabric needed to wrap the cord plus your seam allowance on both sides (for a 5 mm cord and 1.5 cm seam allowance, roughly 5 cm wide is a safe start).
- Join strips if needed. For long runs, seam bias strips together end to end and press the joins open so they don't create a lump.
- Wrap the cord. Fold the strip over the cord, wrong sides together, so the cord sits snugly in the fold and the raw edges line up.
- Sew close to the cord. Fit a zipper foot or a dedicated piping foot and stitch alongside the cord — close, but not so tight that you can't sew over this line later.
- Attach to your project. Lay the covered piping on the right side of one fabric piece, raw edges together, cord facing inward. Sew, then place the second fabric piece on top and stitch the whole sandwich, running just inside your first line so the original stitching disappears.
For corners, snip the piping seam allowance almost to the stitching so it opens and turns cleanly. To finish where the two ends of piping meet, overlap them, trim the cord so the ends butt together, and fold one fabric tail over the join to hide the seam.
Piping for cushions and upholstery
On cushions, piping does two jobs: it sharpens the edge visually and it protects the seam from wear, because the corded ridge takes the rubbing instead of the seam itself. That second point matters on seats that get daily use. For box cushions, run piping around both top and bottom panels for a crisp, tailored look.
For larger upholstery — headboards, sofa arms, seat platforms — use a firmer, larger-diameter cord so the line stays bold under heavy fabric. Because upholstery piping often runs many metres, buy the cord on a continuous reel rather than short pieces, so you avoid joins along visible edges. Choose a cover fabric that either matches the main fabric for a subtle finish or contrasts deliberately for a designed, framed effect.
Making your own vs buying pre-made
Pre-made piping is quick, but you are limited to its colours and cord sizes. Making your own lets you match the exact fabric, pick the precise diameter, and control the seam allowance — which is why most upholsterers keep bare cord in stock and cover it as jobs come in. For production sewing, the standard order quantity is 1,000 m per SKU; if you need a mix of sizes or a smaller trial length, request a quote and we'll advise what's practical for your workshop.
Whichever route you take, the cord is the foundation. A clean, even piping cord under a well-cut bias strip is what turns a soft edge into a defined one.
Frequently asked questions
What is the difference between piping cord and regular cord?
Piping cord is made to be covered by fabric, so it is soft, evenly rounded, and flexible enough to curve around corners without kinking. Regular decorative or utility cord is chosen to be seen and can be stiffer or textured. Using the right piping cord is what gives a piped seam its smooth, consistent profile.
What size piping cord should I use for cushions?
For scatter cushions, a 4-5 mm cord gives a balanced, all-round edge. For firmer seat cushions and sofas, step up to 6-8 mm or larger for a more defined line. Match the cord to the fabric weight — heavier fabric carries a bigger cord well, while thin fabric looks best over a smaller one.
Do I need a special foot to sew piping?
A zipper foot works well because it lets you stitch right alongside the cord. A dedicated piping foot has a groove that guides the covered cord for even more consistent spacing. Either lets you sew close to the cord, which is the key to a tight, professional edge.
Does cotton piping cord shrink?
Natural cotton cord can shrink slightly the first time it gets wet. If the finished item will be washed, pre-shrink the cord and cover fabric together, or allow for it. For upholstery and cushions that stay dry, shrinkage is rarely a concern.