Shirring is rows of elastic gathering sewn on an ordinary sewing machine with elastic thread wound by hand on the bobbin and regular thread on top. Sew parallel rows 1 cm (3/8 in) apart on the right side of the fabric with a 3.5 to 4 mm stitch, holding the earlier rows flat as you go, then steam the finished panel so the elastic shrinks and the fabric gathers to about half its cut width. Cut the panel two to two and a half times the finished width, and finish the top edge before you start.

What is shirring and how does elastic thread work?

Shirring is the stretchy, textured panel on the bodice of a sundress, the waist of a skirt or the cuff of a puff sleeve. Each row is a normal straight stitch from above; underneath, the bobbin thread is a thin elastic cord that was stretched slightly as it was wound and sewn. When the row is finished, the elastic relaxes and pulls the fabric into tiny gathers. Twenty rows of it make a bodice that stretches over the bust and holds without a zip.

It is not the same as smocking, which is hand embroidery over pleats, though the look is related. And unlike sewing elastic directly to fabric, shirring needs no separate elastic: the thread is the elastic.

What do you need?

  • Elastic thread, sold on small spools, usually white or black. One spool shirrs roughly a bodice panel; buy two for a dress.
  • Regular all-purpose polyester thread for the needle, matching the fabric.
  • A universal 80/12 needle.
  • A lightweight woven fabric: cotton lawn, voile, double gauze, poplin, viscose challis or a light linen blend. Heavy fabrics do not gather enough.
  • A water-soluble pen or chalk, a ruler, a steam iron.

How do you wind elastic thread on the bobbin?

Wind it by hand. Hold the empty bobbin in one hand and turn it while feeding the elastic thread with the other, with a light, even tension: the thread should be slightly stretched, not pulled tight and not slack. Fill the bobbin to about three-quarters. A machine-wound bobbin pulls the elastic far too tight on most machines, and the result either does not gather or gathers unevenly.

Drop the bobbin in as usual and bring the elastic up through the needle plate. Sew a test row on a scrap of the garment fabric. If the fabric does not gather at all, wind the next bobbin with a little more stretch, or lengthen the stitch; if the row snaps or the needle thread shows as loops underneath, loosen the needle tension by one number.

Note: Some computerized machines with a drop-in bobbin sense the thicker elastic and refuse to sew, or gather weakly. A front-loading bobbin case can be adjusted by its screw; on a drop-in machine, a slightly fuller hand-wound bobbin and a longer stitch usually solve it. Test before you commit a whole panel.

How do you sew shirring, step by step?

  1. Cut wide. Cut the panel 2 to 2.5 times the finished width. For a bodice that should measure 80 cm (31 1/2 in) around, cut 180 cm (71 in) in total, split between front and back. Shirring works on the straight grain, so cut the rows parallel to the crossgrain.
  2. Finish the top edge first. A narrow double-fold hem of 1 cm (3/8 in), or a casing for a thin elastic. It is much harder to hem a panel once it is gathered.
  3. Mark the first row 2 cm (3/4 in) below the finished top edge on the right side. You only need to mark the first row; the presser foot edge guides the rest.
  4. Set the machine. Stitch length 3.5 to 4 mm, normal needle tension, regular thread on top. Leave 10 cm (4 in) thread tails at the start.
  5. Sew the first row with the right side of the fabric up, so the elastic is on the wrong side. Backstitch two or three stitches at each end, or knot the tails by hand.
  6. Sew the next rows 1 cm (3/8 in) apart, using the right edge of the presser foot against the previous row as your guide. From the second row onward, hold the fabric flat in front of and behind the needle so the earlier gathers are stretched out while you sew; otherwise the rows wander and the gathers bunch.
  7. Keep going until the panel is as deep as you want: 8 to 10 rows for a waistband, 15 to 25 rows for a bodice. Rewind a bobbin whenever one runs out, and overlap the join by 2 cm (3/4 in).
  8. Steam. Hold the iron 1 to 2 cm above the panel and steam it generously without touching, then let it cool. The elastic shrinks and the gathers tighten noticeably. This is the step that turns a loosely rippled panel into real shirring.
  9. Sew the seams. Join the side seams with the panels stretched flat under the foot, stitching over the elastic ends to anchor them. A second row of stitching 3 mm inside the first stops the elastic from working loose.

How much does fabric shrink with shirring?

Expect the panel to end up at 45 to 55 percent of its cut width after steaming, with lighter fabrics gathering more. The stretch of the finished panel is roughly the difference: a bodice cut at 180 cm and gathered to 85 cm stretches back out to about 150 cm (59 in), far more than any body needs to pull it on. Always measure a shirred test square of 20 cm (8 in) before you cut the real pieces; if it shrinks to 11 cm, your ratio is 1.8 and you can plan the cut width from that. The gathering ratio calculator does the arithmetic once you know the ratio.

Common mistakes with shirring

  • Winding the bobbin on the machine: too tight, so the fabric does not gather, or the elastic breaks mid-row.
  • Sewing with the wrong side up: the elastic then sits on the outside of the garment.
  • Rows too close or too far apart. Below 8 mm (5/16 in) the gathers barely show; above 1.5 cm (5/8 in) the fabric puffs between rows. 1 cm is the usual spacing.
  • Not holding the fabric flat from the second row on, which bends the rows.
  • Skipping the steam. Without it the panel looks underpowered. Steam is not optional; it is what makes elastic thread shrink.
  • A heavy or stiff fabric. Quilting cotton shirrs, but stiffly; lawn, voile and challis shirr beautifully.
  • Forgetting that the panel is now narrower. Join it to unshirred pieces only after steaming, and stretch it flat to sew.

When should you use shirring instead of gathering or an elastic casing?

Use shirring when you want a fitted, stretchy section with texture and no visible elastic: a sundress bodice, a shirred waist on a gathered skirt, a sleeve hem, a strapless top that stays up by itself. It replaces zips and buttons and fits a range of sizes.

Use ordinary gathering when the fullness is sewn into a fixed seam, such as a skirt onto a bodice: there is no elastic and no stretch, and the gathers are controlled by the seam. Use an elastic waistband casing when you need one strong, wide band at the waist of trousers or a skirt rather than a soft panel. The comparison of gathering methods sets the three side by side with their looks and limits.