Sewing a collar onto a shirt body takes about 30 to 45 minutes once you have the pieces cut and interfaced
A shirt collar is sewn in two stages: first you stitch the two collar pieces together around three sides, turn it right-side out, and press it flat. Then you attach that finished collar to the neckline of the shirt body using a combination of machine stitching and hand stitching. The hand stitching at the end is what makes the collar look professional—it closes the seam on the underside so no raw edges show.
You will need the collar pieces already cut from your pattern, interfacing (a stiff fabric layer that gives the collar shape), a needle, thread that matches your fabric, pins, scissors, an iron, and either a sewing machine or needle and thread for hand sewing. If you are using a machine, a walking foot helps feed thick layers evenly, but it is not required.
Key Takeaways
- Fuse interfacing to the underside of one collar piece before you sew anything, following the interfacing package directions for heat and pressure.
- Sew the two collar pieces together with a 5/8-inch seam allowance on three sides, leaving the neckline edge open, then trim the seam allowance and turn the collar right-side out.
- Baste the finished collar to the shirt neckline by hand with long, loose stitches, then machine-stitch it in place using a 5/8-inch seam allowance.
- Fold the underside seam allowance inward and hand-stitch it closed with a ladder stitch or slip stitch so the seam does not show from the front.
- Press the collar flat with an iron after sewing to set the shape and remove wrinkles.
Prepare the collar pieces with interfacing
Interfacing is a layer of stiff fabric that you fuse to one side of your collar using heat and moisture. It prevents the collar from drooping and gives it a crisp, finished look. Cut a piece of interfacing the same size as one of your collar pieces—usually the piece that will be the underside of the collar when worn.
Follow the directions on your interfacing package for heat and steam. Most fusible interfacing requires a hot iron (around 350°F) and steam for 10 to 15 seconds. Place the interfacing shiny-side down on the wrong side of your collar piece, lay a damp cloth on top, and press firmly with the iron. Let it cool for a few seconds before lifting the cloth. The interfacing should feel bonded to the fabric and not peel away when you tug it gently.
Sew the two collar pieces together
Place the two collar pieces with right sides facing each other—the pretty sides touching, the wrong sides facing out. Pin around three sides: the two short ends and the long outer edge. Leave the neckline edge (the straight edge that will attach to the shirt) unpinned and open.
Sew along the three pinned sides using a 5/8-inch seam allowance. If you are using a machine, sew slowly around the corners and backstitch at the start and end. If you are sewing by hand, use a running stitch or backstitch and keep your stitches small and even, about 1/8 inch apart. Sew all the way to the corner on each end but do not sew past the neckline edge.
Trim the seam allowance down to 1/4 inch on the three sewn sides, cutting away the extra fabric close to your stitching line. Trim the corners diagonally, cutting off the corner point about 1/8 inch away from the stitching. This reduces bulk so the collar lies flat when you turn it.
Turn the collar right-side out through the open neckline edge. Use a point turner or the blunt end of a chopstick to push the corners out fully. Press the collar flat with an iron, paying special attention to the edges so they are crisp and even.
Baste the collar to the shirt neckline
Basting means sewing with long, loose stitches that hold pieces in place temporarily before you sew them permanently. This step prevents the collar from shifting while you machine-stitch it.
Pin the collar to the neckline of the shirt body with the interfaced side facing down (toward the inside of the shirt). The raw neckline edge of the collar should line up exactly with the raw neckline edge of the shirt. Match the center of the collar to the center back of the neckline, then match the collar ends to the front edges of the shirt. Pin every 2 to 3 inches around the curve.
Hand-baste the collar in place using a needle and thread with long, loose stitches about 1/4 inch long. Sew all the way around the neckline. These stitches will be removed later, so they do not need to be perfect—they just need to hold the collar steady while you machine-stitch.
Machine-stitch the collar to the neckline
Machine-stitch the collar to the shirt using a 5/8-inch seam allowance, sewing right over the basting stitches. Start at one front edge and sew all the way around the neckline to the other front edge. Backstitch at the start and end. Sew slowly around the curve so the fabric feeds evenly and the seam stays straight.
Remove the basting stitches by gently pulling on the thread and picking them out with a seam ripper or small scissors. Press the seam flat with an iron, pressing from the inside of the shirt so the seam allowance lies flat against the interfacing.
Hand-stitch the underside seam closed
This step hides the raw edges on the inside of the shirt so the collar looks finished from both sides. Fold the seam allowance of the underside collar piece inward along the neckline, tucking the raw edge inside by about 1/4 inch. Pin it in place so it covers the machine stitching line.
Use a ladder stitch (also called a slip stitch) to close this seam by hand. Thread a needle with thread that matches your fabric. Bring the needle up through the fold of the collar seam allowance, then slide the needle horizontally inside the fold for about 1/4 inch. Bring the needle back out and cross over to the shirt body, inserting the needle directly across from where you came out. Slide the needle inside the shirt fabric for 1/4 inch, then come back out and cross back over to the collar. Repeat this zigzag pattern all the way around the neckline. The stitches will be nearly invisible because they run inside the fold.
Make your stitches small and keep them close together—about 1/8 inch apart—so the seam does not gap open. Pull the thread snug as you go, but not so tight that it puckers the fabric.
Press and finish the collar
Once all the hand stitching is complete, press the entire collar and neckline area with an iron to set the shape and remove any wrinkles from handling. Press from the inside first, then flip the shirt and press from the outside. Use steam if your fabric is cotton or linen, and a lower heat setting if your fabric is synthetic or a blend.
The collar should now lie flat and smooth, with no visible seams or raw edges on either side. If you see any gaps where the underside seam did not close completely, go back and add a few more ladder stitches to close them.
Frequently Asked Questions
What happens if I sew the collar on backwards?
If you sew the collar with the interfaced side facing outward instead of inward, it will look stiff and the interfacing will show. You will need to remove all the stitches and resew it. To avoid this, always check that the interfaced side is facing down toward the inside of the shirt before you pin and baste.
Can I use a sewing machine for the final hand-stitching step?
You can use a machine for the entire collar if you prefer, but the hand stitching on the underside creates a more professional finish because it is invisible from the front. If you machine-stitch both sides, the seam will show on the inside of the shirt. Some sewers use a machine for speed and accept the visible seam.
My collar is puckering around the neckline. What went wrong?
Puckering usually means the seam allowance is too wide or the fabric was stretched while sewing. Make sure you are using a 5/8-inch seam allowance and sewing slowly around the curve. If the collar is already sewn, you can press it firmly with steam to relax the puckers, though they may not disappear completely.
How do I know if my interfacing is fused on correctly?
Gently tug on the interfacing after it cools. It should feel bonded to the fabric and not peel away. If it lifts or feels loose, the iron was not hot enough or you did not hold it long enough. Fuse it again, making sure the iron is at the temperature listed on the package and you explore steam.
Do I have to hand-stitch the underside, or can I fold it and topstitch?
You can fold the seam allowance inward and topstitch it from the outside using a machine, which is faster. The stitching will be visible on the front of the collar, so use thread that matches your fabric. This method is common on casual shirts and gives a different look than the invisible ladder stitch.