Welting and Cushions

Welt

Welt (piping, cording) is a fabric-covered cord sewn into seams and along edges. It defines lines, strengthens seams, and hides the joint between pieces. The Montana bulletin calls for cable cord covered with a 2-inch strip of the cover fabric or a harmonizing fabric of equal wear ¹.

To make welt:

1. Cut strips about 1 1/2 to 2 inches wide (wider for thick cord) ¹. Cut on the bias (45° to the grain) for curves - bias strips bend smoothly; straight grain is fine for straight runs and saves fabric.
2. Join strips end to end with diagonal seams to reduce bulk.
3. Wrap the cord in the strip, right side out, raw edges together.
4. Sew close to the cord with a welting (piping) or zipper foot.

To set welt in a seam: sew the welt to one piece, raw edges matching, then sew the second piece over it, stitching just inside the first line so no stitches show. At corners, clip the welt allowance so it turns cleanly. To end welt, open the casing, cut the cord to butt the start, fold the fabric end under, and overlap.

On a frame, welt is sewn or stapled along the top edge, with the band or skirt attached below it ¹.

Boxed cushions

A boxed cushion has a top, a bottom, and a boxing strip around the sides, with welt in the top and bottom seams.

Pattern: trace the seat (or the old cushion) on paper, true up the shape, and add seam allowance (commonly 1/2 inch). Cut top and bottom with motifs centered and pile running front to back.

Boxing: cut the side strip the cushion thickness plus two seam allowances. Put a zipper in the back boxing, extending around the back corners a few inches so the foam goes in easily: sew two half-width strips to the zipper tape to make a zipper panel the same width as the boxing.

Sewing:

1. Sew welt around the top and bottom pieces.
2. Starting at the back, sew the boxing to the top, matching corners, clipping the boxing allowance at corners so it turns.
3. Join the boxing ends.
4. Sew the bottom to the boxing, aligning corners exactly with the top, so the cushion isn’t twisted.
5. Turn right side out.

Stuffing: cut the foam slightly larger than the finished size (about 1/2 inch in width and depth) and wrap it in polyester batting (see Foam, Wraps, and Flammability). Fold the foam in half like a taco, slide it in through the zipper, and work it into the corners. A thin plastic sheet around the foam makes it slide in; pull it out afterward.

Leather and vinyl

Leather and vinyl don’t fray, so welt casings can be cut narrower, but they need a walking-foot machine, leather needles, and longer stitches; pins leave holes, so use clips.

What to take from this

Welt is cord wrapped in bias strips (for curves) or straight strips, sewn with a welting or zipper foot and set into seams by stitching inside the first line. Boxed cushions have welted top and bottom pieces joined by a boxing strip with a zipper wrapping the back corners; match corners exactly, and stuff slightly oversize batting-wrapped foam folded through the zipper.