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How to Sew Boning Into A Bodice


Boning is a narrow strip of plastic or metal sewn into seams or casings used to build structure and support into garments. It’s called boning because years ago bones were used in place of plastic or metal. It’s most commonly sold by the yard as hard plastic in a soft feltlike fabric casing or as thin flat plastic boning that you can sew through without a fabric casing. Metal boning is harder to find and may have to be ordered from specialty websites. Metal boning, also called spiral-steel boning, is more flexible, bends with the body and may be more comfortable to wear.

Boned bodice (Simplicity 4931)

Boned bodice (Simplicity 4931)

Boned bodice, detail

Boned bodice, detail


Boning is frequently seen in strapless dresses, halter tops, structured bodices, corsets, foundation garments and other tight-fitting garments. Boning helps smooth out the lines of a bodice. It holds the seams straight and keeps them from wrinkling. Boning is sewn along straight, vertical seams, including side seams, princess seams and center seams. Boning can be sewn on either side of a zipper for extra support. Sometimes you will even see boning sewn on an angle to help support the lines of the garment. You won’t be able to see the boning from the right side of the garment, but you may see the topstitching lines of each casing. Sometimes the casings are sewn to the outside as a design feature, as seen in corsets or foundation garments.

Tips + Notes

  • You don’t want to skip boning if your dress is strapless, especially if the pattern calls for boning. It’s necessary to support the bodice and keep the dress from falling down.
  • You can buy metal boning by the yard or meter or in precut lengths. If you need to shorten metal boning, you’ll need wire cutters. End caps cover the cut ends and are applied with pliers.


In this example, I’m using the type of boning that comes in the fabric casing. I am applying the boning to the lining of the bodice, so the casing seams are visible only inside the garment, not from the outside.

First, you’ll construct the bodice lining. Sew all princess seams or darts, and sew side seams of bodice front and back. Leave the bodice open at the closure seam. In this case, the closure is a left side zipper. Press darts and press seam allowances open. Trim seam allowances to ¼” (6mm). Trimming (page link) is optional, but it helps to reduce bulk, if necessary.

If the pattern calls for boning, it will indicate which seams require boning. If not, decide where you want to add the boning. At minimum, you’ll want to add a piece of boning to each side seam. Those two pieces will add structure and help keep your dress up. Depending on the design, you may want to add boning to the vertical seams as well, along the vertical darts at the back or along center front or back. The more boning you add, the more structured your bodice will be.

How to sew boning into a bodice (1)

Measure the seams where you want to add the boning, and cut the boning to match the seam lines. You’ll need one piece of boning in its casing for each seam.

How to sew boning into a bodice (2)

Take the boning out of its casings. You’ll have curly plastic strips. To straighten out the boning pieces, fill a shallow dish with boiling water and drop the plastic pieces into the water. Leave the boning in the hot water for five to ten minutes, using a mug or dish to hold the pieces under water. Take the pieces out and press them flat under something heavy while they cool off. (If you’re not able to soften the boning in hot water, alternate the direction of the curl as you insert each piece into its casing so that they don’t curve the same way. Over time they should straighten out.)

How to sew boning into a bodice (3)

Center the casings along the seam lines or dart lines, and pin to the bodice. Pin all of the casings in place. Edgestitch (page link) on either side of the casing, through the original casing stitch lines, with your sewing machine.

How to sew boning into a bodice (4)

Before inserting the boning back into the casing, trim ¾” (1.9cm) off each end. You do this is to make sure you don’t stitch through the boning when you sew your top and bottom seam allowances. Cut the ends in a slight curve to remove the corners. With a nail file, file the ends into a slight arc to smooth out any sharp points. Alternately you can melt the ends carefully with a match or lighter. The ends will form a hard knob without any sharp edges.

How to sew boning into a bodice (5)

Insert the boning into the casings, and check to make sure each piece ends at least 5⁄8″ (1.5cm) from the raw edge. Sew across each of the casing openings to keep the boning inside its casing.

How to sew boning into a bodice (6)

Voila! Your boned bodice is complete.


How to sew the sew through type of boning

If you are using the sew-through type of boning, follow the same steps as above, cutting the boning pieces shorter than each seam by ¾” (1.9cm) on each end. Instead of sewing the fabric casings to the bodice, center the boning over the seam line, and edgestitch (page link) along both edges right through the boning.

Source : The Sewtionary An A to Z Guide to 101 Sewing Techniques + Definitions
About the Author : Tasia ST. Germaine