The basic steps for attaching a collar

Sewing a collar onto a garment means stitching the collar piece to the neckline opening so it sits flat and stays in place. The process has four main steps: prepare the collar, pin it to the neckline, stitch it down, and finish the raw edges. Most collars are sewn with a straight stitch on a machine, though hand sewing works too if you prefer. The whole job usually takes 30 to 60 minutes depending on the collar style and your experience.

The collar itself is typically made from two fabric pieces sewn together and turned right-side out before it ever touches the garment. If you are working from a pattern, the pattern will tell you whether to make the collar first or if it comes pre-made. Either way, the collar arrives at the neckline as a finished piece ready to attach.

Key Takeaways

  • Pin the collar to the neckline with the raw edges aligned and the collar facing inward before you stitch, so the seam allowance stays hidden when you fold it.
  • Use a 5/8-inch seam allowance (or whatever your pattern specifies) and stitch slowly around the curve of the neckline to keep the line even.
  • After stitching, trim the seam allowance to 1/4 inch and clip the curves so the collar lies flat when you fold it outward.
  • Finish the raw edges with a zigzag stitch or pinking shears to stop fraying, then press the collar with an iron to set the fold.

Prepare the collar and neckline before pinning

Start by checking that your collar is finished — both pieces sewn together, turned right-side out, and pressed flat. The raw edges should be at the bottom, where they will meet the neckline. If your pattern calls for interfacing (a stiff backing fabric), it should already be fused to the underside of the collar.

Next, mark the center of the neckline and the center of the collar with a pin or a small chalk mark. On most garments, the center front of the neckline is where the two front pieces meet, and the center back is at the middle of the back piece. Mark the collar the same way — fold it in half lengthwise and mark the fold. Matching these points first keeps the collar from twisting as you pin.

If your neckline has a facing (a separate fabric strip that finishes the edge), you will stitch the collar between the garment and the facing. If there is no facing, you will stitch the collar to the garment and then fold the seam allowance to the inside and hand-stitch it closed. Check your pattern to see which method applies.

Pin the collar to the neckline with the right sides together

Lay the garment flat with the neckline facing up. Place the collar on top of it with the right side of the collar facing down — this means the finished, visible side of the collar is touching the right side of the garment. The raw edges of the collar should line up exactly with the raw edge of the neckline. This inside-out position is what lets you hide the seam when you fold the collar outward later.

Start pinning at the center marks you made, then work outward toward the shoulders. Space pins about 2 inches apart around the entire neckline. At the corners where the collar meets the front edges, pin carefully so the collar sits flat without puckering. If the neckline is curved (as most are), the collar will need to curve with it — pin gently and do not stretch the fabric.

Once the collar is pinned all the way around, try the garment on or hold it up to check that the collar sits evenly and does not twist. If it does, unpin that section and repin it. Taking time here saves you from having to rip out stitches later.

Stitch the collar to the neckline with a straight stitch

Thread your machine with thread that matches the garment (not the collar, unless they are the same color). Set the stitch length to a medium setting — about 2.5 on most machines — and use a straight stitch. Attach a walking foot if you have one; it helps feed thick seams evenly.

Starting at one shoulder seam, stitch slowly around the neckline using the seam allowance your pattern specifies (usually 5/8 inch). Keep your hands relaxed and let the machine do the work. As you approach curves, slow down even more and pivot the needle in and out of the fabric to follow the curve smoothly. Do not stretch the fabric as you sew — this causes puckering.

Stitch all the way around the neckline and overlap your stitches by about 1/2 inch where you started and ended. Backstitch at the beginning and end to lock the thread. Remove the pins as you go or after you finish stitching.

Trim and clip the seam allowance so the collar lies flat

Once the collar is stitched, trim the seam allowance down to 1/4 inch. Use sharp scissors or a rotary cutter and cut parallel to your stitching line. This reduces bulk so the collar does not look lumpy when you fold it outward.

Next, clip the curves. Make small cuts (about 1/8 inch long) perpendicular to the seam, spaced about 1/2 inch apart all the way around the neckline. Clip right up to the stitching line but do not cut through it. These clips let the seam allowance spread out as the collar curves, so it lies smooth instead of bunching.

If your neckline has a facing, you are almost done — the facing will cover these raw edges. If there is no facing, you will need to fold the seam allowance to the inside of the garment and hand-stitch it closed with a ladder stitch or whip stitch. Your pattern will show you how.

Finish the raw edges and press the collar

To stop the raw edges from fraying over time, finish them with a zigzag stitch or pinking shears. If you are using a zigzag stitch, set your machine to a medium width and length and stitch along the trimmed edge of the seam allowance. If you prefer pinking shears (scissors with a zigzag blade), straightforward cut along the edge of the seam allowance after you have trimmed it.

Once the edges are finished, turn the collar outward so the right side faces up and the seam is hidden inside. Press the neckline seam with an iron set to the heat appropriate for your fabric. Press from the underside first (the side that will be hidden), then flip and press the top side. This sets the fold and makes the collar sit flat and crisp.

If your pattern calls for topstitching (a visible line of stitching near the edge), do that now while the collar is still fresh and the seam is sharp. Topstitching is optional but adds a professional finish and helps hold the seam in place.

Frequently Asked Questions

What if my collar puckers or twists after I stitch it?

Puckering usually means you stretched the fabric as you sewed or did not clip the curves enough. Twisting means the collar was not pinned evenly to the neckline. If the problem is small, you can often fix it by pressing firmly with an iron and a damp cloth. If it is severe, you may need to rip out the stitches and start over — it is faster than trying to wear a collar that does not sit right.

Can I sew a collar on by hand instead of with a machine?

Yes. Use a backstitch or running backstitch and follow the same steps — pin with right sides together, stitch along the seam line, trim and clip, then fold outward and press. Hand sewing takes longer but gives you more control on curves and is quieter. Use thread that matches the garment and keep your stitches small and even.

Do I need a facing to attach a collar?

No, but a facing makes the job easier because it covers the raw edges and seam allowance on the inside. Without a facing, you have to fold the seam allowance to the inside and hand-stitch it closed, which takes extra time. Your pattern will tell you whether a facing is included.

How do I attach a collar to a knit neckline?

Knit fabrics stretch more than woven ones, so use a ballpoint needle and a stretch stitch (or a narrow zigzag) instead of a straight stitch. Stabilize the neckline with a strip of fusible interfacing or elastic tape sewn to the seam allowance before you attach the collar. This keeps the neckline from stretching out of shape.

What is the difference between a collar and a facing?

A collar is a separate piece that stands up or folds down and frames the neckline — it is visible and part of the garment's design. A facing is a strip of fabric that finishes the raw edge of the neckline on the inside — it is hidden and purely functional. Many garments have both.