The Basic Process for Attaching a Collar

Sewing a collar means stitching a separate fabric piece to the neckline of a garment so it stands up, folds over, or lies flat depending on the style. The core steps are the same whether you're working on a shirt, dress, or jacket: you'll interface the collar pieces for structure, sew them together, attach the collar to the garment body, and finish the raw edges. Most collars take 30 to 45 minutes once you have your pattern pieces cut and ready.

The method shown here works for a basic flat collar (the kind that lies against the shoulders) or a stand collar (the kind that stands up around the neck). Both use the same attachment technique—the difference is in how you press and finish after sewing.

Key Takeaways

  • Interface both collar pieces with fusible interfacing before sewing them together, which gives the collar shape and prevents it from drooping.
  • Sew the two collar pieces right sides together, trim the seam allowance at corners and curves, and turn it right side out before attaching to the garment.
  • Baste the collar to the neckline with the raw edges aligned, then sew through all layers using a 5/8-inch seam allowance.
  • Finish the raw edges by sewing a facing or bias tape over them on the inside of the garment to hide the seams and prevent fraying.
  • Press the collar after each major step—after interfacing, after turning, and after final attachment—so it holds its shape.

Prepare Your Collar Pieces with Interfacing

Start with two collar pieces cut from your pattern. Lay one piece on your ironing board with the wrong side facing up. Cut a piece of fusible interfacing (the kind with adhesive on one side) slightly smaller than the collar piece—about 1/4 inch away from all edges. Place the interfacing adhesive-side down on the wrong side of the collar.

Set your iron to the heat recommended on the interfacing package (usually medium to medium-high). Press the iron down firmly for 10 to 15 seconds, then lift and move to the next section. Do not slide the iron back and forth—pressing straight down bonds the interfacing better. Repeat for the second collar piece. Let both pieces cool for a minute before handling them. The interfacing should feel permanently fused to the fabric and not peel up at the edges.

Sew the Two Collar Pieces Together

Place the two collar pieces with right sides together (the pretty sides facing each other, the interfaced sides facing out). Pin around three sides, leaving the long straight edge that will attach to the neckline unpinned. This unpinned edge is called the neck edge.

Thread your machine and set it to a straight stitch with a stitch length of 2.5 mm. Sew around the three pinned sides using a 5/8-inch seam allowance (the standard for garment sewing). Start at one corner of the neck edge and sew to the first corner, pivot with the needle down, and continue around. Backstitch at the start and end to lock the thread.

After sewing, trim the seam allowance to 1/4 inch using scissors or a rotary cutter. At the corners, cut diagonally across the corner point, cutting close to the stitching but not through it. This removes bulk so the corners lie flat when you turn the collar right side out. Clip into any curved edges (if your collar has curves) by making small cuts perpendicular to the seam, about 1/4 inch apart. Do not cut through the stitching.

Turn the Collar Right Side Out and Press

Reach into the opening at the neck edge and gently pull one corner of the collar through. Keep pulling until the entire collar is turned right side out. Use a point turner (a small plastic tool) or the blunt end of a chopstick to push the corners out from the inside so they are sharp and square.

Lay the collar flat on your ironing board with the seams at the edges. Press from the interfaced side (the back) using medium heat. The seams should roll slightly to the back so the front edge looks crisp. Press the entire collar, paying extra attention to the corners and curves. Let it cool before moving on.

Attach the Collar to the Garment Neckline

Lay your garment body flat with the right side facing up. The neckline should be a smooth curve or straight line where the collar will sit. Place the collar on top with the right side of the collar facing the right side of the garment. The raw neck edge of the collar should line up exactly with the raw neckline edge of the garment.

Pin the collar in place, starting at the center front and working toward each shoulder. Space pins about 2 inches apart. The collar should lie flat against the garment with no puckers or gaps. If the neckline is curved, the collar will naturally curve with it.

Sew the collar to the garment using a 5/8-inch seam allowance. Sew slowly around the entire neckline, removing pins as you approach them. Backstitch at the start and end. After sewing, trim the seam allowance to 1/4 inch and clip into any curves the same way you did on the collar itself.

Finish the Raw Edges with Facing or Bias Tape

The raw seam allowance on the inside of the garment needs to be covered so it does not fray and so the inside looks finished. The two most common methods are a facing (a separate piece of fabric sewn to the inside) or bias tape (a narrow strip of folded fabric that wraps around the edge).

For a facing: Cut a facing piece from your pattern (usually provided) and sew it to the inside of the neckline, right sides together, using the same 5/8-inch seam allowance. Trim the seam, turn the facing to the inside, and press. Topstitch (sew a visible line of stitching) around the neckline from the outside if your pattern calls for it, which holds the facing in place and looks professional.

For bias tape: Fold the bias tape in half lengthwise and press it. Open it out and align one raw edge with the raw seam allowance on the inside of the garment. Sew along the crease line. Fold the bias tape to the back and press so it wraps around the seam allowance. Topstitch from the outside along the neckline to catch the bias tape and hold it permanently in place.

Press and Check Your Finished Collar

After the facing or bias tape is sewn, press the entire neckline area from the outside using medium heat. Press the collar itself so it sits the way you want it—flat against the shoulders for a flat collar, or standing up for a stand collar. The seams should be crisp and the collar should have no wrinkles or puckers.

Check that the collar is symmetrical by looking at it from the front and back. The two sides should match in shape and position. If one side is higher or lower than the other, you may need to adjust the facing or bias tape and press again. Once you are satisfied with the shape, your collar is complete.

Frequently Asked Questions

What is interfacing and why do I need it?

Interfacing is a layer of fabric with adhesive on one side that fuses to your collar fabric when pressed with a hot iron. It stiffens the collar so it holds its shape instead of drooping or wrinkling. Without it, collars look limp and unprofessional. Fusible interfacing is the easiest type for beginners because you straightforward press it on—no sewing required.

My collar is puckering at the neckline. What went wrong?

Puckering usually means the collar was stretched slightly as you sewed it to the garment, or the neckline curve did not match the collar curve exactly. Unpick the stitches, repin the collar more carefully, and sew again. If the problem persists, check that your pattern pieces are cut correctly and that the neckline seam allowance is trimmed evenly all the way around.

Can I sew a collar without a pattern?

It is possible but difficult for beginners. A pattern gives you the exact shape and size needed for your garment. If you want to try without one, measure your neckline, sketch a collar shape on paper, and test it on scrap fabric first. Most home sewers use a pattern because it saves time and ensures the collar fits properly.

How do I know if my seams are sewn straight?

Look at the seam from both sides. It should be a thin, even line with stitches the same distance apart all the way around. If the line wavers or the stitches are uneven, you may have pulled the fabric or moved the needle position. Practice on scrap fabric to build muscle memory for keeping the fabric edge aligned with the presser foot guide.

What if my collar corners are not sharp after turning?

Use a point turner or chopstick to gently push the corner out from the inside. Press the corner with the iron to set the shape. If the corner is still rounded, you may not have trimmed the seam allowance close enough at the corner before turning. Next time, trim the corner seam allowance to 1/8 inch for sharper points.