Sewing straps on a dress takes about 30 minutes once you have the strap pieces ready
The fastest method is to fold your strap fabric in half lengthwise, sew it closed on a machine, turn it right-side out, and then stitch it to the dress at the armhole or neckline. If you are sewing by hand, you will use a ladder stitch to close the strap and a backstitch to attach it — both are slower but give you more control over placement. Either way, you need to pin the strap in place first, sew it down, and then reinforce the seam where the strap meets the dress body, because that joint takes the most stress when you wear it.
The strap itself should be cut from the same fabric as your dress or from a coordinating fabric, and it should be about 1.5 inches wide before you fold and sew it. If your dress pattern came with strap pieces, use those measurements. If you are adding straps to a dress that did not have them, measure the distance from one shoulder point to the other across the back or front, add 1 inch for seam allowance, and cut two strap pieces to that length.
Key Takeaways
- Cut strap fabric 1.5 inches wide and long enough to span from one shoulder to the other, plus 1 inch for seam allowance.
- Fold the strap in half lengthwise with right sides together, sew the long edge closed, and turn it right-side out so the seam is hidden inside.
- Pin the finished strap to the dress at both ends, matching raw edges to the armhole or neckline seam, then sew it down with a 0.5-inch seam allowance.
- Reinforce the strap attachment by sewing over the seam a second time or using a box stitch pattern, because this joint bears the weight of the dress when you wear it.
Prepare and sew the strap tube on a machine
Cut two strap pieces from your fabric, each 1.5 inches wide and the length you measured. Place them right sides together — the pretty sides facing each other — and pin along one long edge. Sew a straight seam down that edge using a 0.5-inch seam allowance and a stitch length of 2.0 to 2.5 millimeters. Backstitch at the start and end to lock the thread.
Trim the seam allowance down to 0.25 inch to reduce bulk when you turn the strap. Clip the corners at a 45-degree angle, cutting close to the stitching but not through it — this helps the corners lie flat once the strap is turned right-side out. Turn the strap through the opening at one end, using a point turner or the blunt end of a chopstick to push the corners out fully. Press the strap flat with an iron, making sure the seam runs down the center of one side.
Close the open end of the strap by hand
You left one short end of the strap open so you could turn it right-side out. Close that end with a ladder stitch, which is invisible from the outside. Fold the raw edges of the opening inward by 0.5 inch and press them flat. Thread a needle and knot the end, then bring the needle up through the fold on one side of the opening.
Cross to the opposite side and insert the needle directly across from where you came out, then slide it inside the fold for about 0.25 inch and come back out. Return to the first side and repeat — you are creating a ladder pattern inside the fold. Pull the thread every few stitches to close the opening. Once the opening is closed, make a few stitches in place at the end and knot off the thread on the inside.
Pin the strap to the dress at both ends
Lay the dress flat on a table with the inside facing up. Position one finished strap so that one short end aligns with the raw edge of the armhole or neckline seam on one side. The strap should sit on top of the dress fabric, with its raw edge matching the dress's raw edge. Pin it in place, using two or three pins to hold it steady.
Repeat on the other side with the second strap, making sure both straps are the same distance from the center front or back. Step back and look at the dress from the outside to check that the straps sit where you want them. Adjust the pins if needed before you sew. The strap ends should be caught in the seam when you sew the armhole or neckline binding, or you can sew them down separately if the dress is already finished.
Sew the strap to the dress with a reinforced seam
Set your machine to a straight stitch with a 0.5-inch seam allowance. Sew along the edge where the strap meets the dress, starting and ending with a backstitch. Sew slowly and keep the raw edges aligned under the presser foot. Once you have sewn the strap down once, sew over the same seam a second time to reinforce it — this is where the dress will experience the most stress.
Alternatively, use a box stitch pattern: sew a rectangle around the strap end, starting at one corner, sewing down the side, across the bottom, up the other side, and back to the start. This creates four lines of stitching in a box shape and is even stronger than a double seam. Trim any loose threads and press the seam flat with an iron.
Sew straps by hand if you do not have a machine
Hand sewing takes longer but works just as well. Cut your strap pieces and fold them in half lengthwise with right sides together. Thread a needle and knot the end. Use a backstitch to sew the long edge closed, making stitches about 0.25 inch long. A backstitch means you bring the needle up through the fabric, go back and insert it behind where you came out, then come up ahead of that point and repeat.
Once the strap is sewn closed, turn it right-side out and close the open end with a ladder stitch as described above. Pin the strap to the dress and use a backstitch to sew it down, again making stitches about 0.25 inch long. Sew the strap down twice for reinforcement, or use a box stitch pattern by sewing a rectangle around the strap end.
Avoid common mistakes when attaching straps
The most common error is sewing the strap on with only one line of stitching. Because the strap bears the weight of the dress when you wear it, a single seam will eventually tear. Always reinforce by sewing the seam twice or using a box stitch. Another mistake is not trimming the seam allowance inside the strap tube before turning it — this creates a bulky, lumpy strap that does not lie flat.
Do not sew the strap ends closed before attaching them to the dress. The raw edges of the strap should be caught in the dress seam, which holds them securely. If you close the strap ends first, they will fray and come loose. Finally, make sure the strap is long enough to reach comfortably from one shoulder to the other without pulling. If the strap is too short, it will strain the neckline or armhole seam and may tear the dress.
Frequently Asked Questions
Can I add straps to a dress that already has a finished neckline?
Yes, but it is more work. You will need to unpick a small section of the neckline binding where each strap will attach, insert the strap end into that opening, and then resew the binding closed over the strap. Alternatively, you can sew the strap on top of the finished neckline using a ladder stitch, which is invisible from the outside but takes longer than machine sewing.
What fabric should I use for straps?
Use the same fabric as your dress if possible, so the straps blend in. If that fabric is too thick or stretchy, use a coordinating cotton or linen. Avoid very stretchy fabrics like spandex or jersey unless you interface them first with a fusible stabilizer, which prevents them from sagging under the weight of the dress.
How wide should the finished strap be?
A finished strap is usually 0.75 inch wide, which is comfortable to wear and strong enough to support the dress. If you want a thinner strap, cut the fabric 1.25 inches wide instead of 1.5 inches. Do not go narrower than 0.5 inch, because very thin straps are uncomfortable and may tear.
What if my strap keeps twisting when I turn it right-side out?
Use a point turner or safety pin to help guide the strap as you turn it. Push the point turner through the strap tube from the open end, grab the fabric at the far end, and pull it back through. This is slower than turning by hand but gives you more control and prevents twisting.
Do I need to interface the strap fabric?
Interfacing is optional for most fabrics. If your dress fabric is lightweight or stretchy, add a lightweight fusible interfacing to one side of the strap fabric before you fold and sew it. This makes the strap more stable and prevents it from sagging. Follow the interfacing package directions for heat and pressure settings.