1. Measure and Cut the Ribbing

• Measure the garment opening where ribbing will attach (neckline, armhole, cuff, or hem) with a flexible measuring tape, keeping fabric flat but not stretched.
• Multiply the opening measurement by 0.75 to 0.80 for standard ribbing (e.g., 20 in neckline × 0.75 = 15 in ribbing length); use 0.80 for less snug fit or less stretchy ribbing.
• For tubular ribbing (neckbands and cuffs): Add 1 in total (1/2 in seam allowance on each end) to your calculated length, then cut the ribbing width equal to twice the desired finished height plus seam allowances (e.g., for a 1 in finished band, cut 2.5 in wide including 1/2 in seam allowances).
• For flat ribbing applied to hems or non-circular openings: Cut length as calculated above; cut width as doubled finished width plus seam allowances.
• Ensure ribs run perpendicular to the long edges (parallel to the short ends) so stretch runs around the opening.

2. Prep Tubular Ribbing (for neckbands and cuffs)

• Fold the ribbing strip in half lengthwise with wrong sides together so raw edges align; press lightly to crease the fold.
• With right sides together, align the short raw ends of the ribbing and stitch with 1/2 in seam allowance to form a loop; press seam open or to one side.
• You now have a folded loop of ribbing with a seam and two raw edges.

3. Mark Quarters for Even Distribution

• On the ribbing loop: Fold in half to locate the point opposite the seam; mark with a pin or chalk. Fold again to divide into quarters; mark each quarter point.
• On the garment opening: Identify the center front, center back, and both shoulder seams (or side seams for armholes or cuffs); mark each quarter point.
• For ribbing without a seam (like binding): Mark the starting point and divide the loop into even quarters.

4. Pin Ribbing to Garment

• With garment right side out (or inside out depending on pattern instructions), align the ribbing loop’s raw edges to the raw edge of the garment opening, right sides together.
• Match the ribbing seam to the center back (or other designated seam) and pin.
• Match and pin each quarter mark on ribbing to the corresponding quarter mark on the garment opening.
• The ribbing will be shorter than the garment opening; do not stretch it yet—just pin the marked points.

5. Sew Ribbing to Garment

• Set your machine to a stretch stitch (narrow zigzag with 1.5 mm width and 2.5 mm length, or a built-in stretch/lightning stitch) or prepare your serger with differential feed set to 0.7-1.0.
• Starting at a seam or pin, place the ribbing on top and the garment against the feed dogs (ribbing on top helps you control the stretch).
• As you sew, gently stretch the ribbing to match the garment edge between each set of pins; do not pull or stretch the garment fabric itself.
• Remove pins just before the needle reaches them; maintain consistent stretch and speed.
• Use a 1/4 to 1/2 in seam allowance as your pattern directs.
• When you reach the starting point, overlap stitches by 1/2 in and backstitch or lock stitches.

6. Finish the Seam Allowance

• If using a sewing machine, trim seam allowance to 1/4 in and finish raw edges with a zigzag stitch, overlock stitch, or serger to prevent fraying and secure stretch.
• If using a serger, seam allowance is trimmed and finished in one pass.
• Press seam allowance toward the garment body (not toward the ribbing) using low heat and light pressure; use a press cloth to protect ribbing.

7. Topstitch (Optional)

• For a professional finish, topstitch from the right side of the garment 1/8 to 1/4 in from the seam using a stretch stitch or twin needle.
• This secures the seam allowance flat and prevents it from flipping up during wear and washing.
• Stretch the fabric slightly as you topstitch to allow the stitches to stretch with the garment.

8. Apply Flat Ribbing to Hems (Alternative Method)

• For flat ribbing on t-shirt hems or sleeve bands (not folded in half): Cut ribbing to calculated length and desired width plus seam allowances.
• Divide and mark quarters on both ribbing and garment hem edge.
• Pin ribbing to garment hem with right sides together, raw edges aligned, matching quarter marks.
• Stretch ribbing evenly as you stitch using a stretch stitch or serger.
• Press seam allowance up into the garment; fold ribbing down or leave flat as pattern directs.
• Topstitch if desired to keep ribbing in place.

9. Troubleshooting Common Issues

• Wavy or rippled ribbing: Ribbing was cut too long or not stretched enough during sewing—recut at 70-75% of opening and redistribute evenly.
• Stretched-out garment edge: Main fabric was pulled during sewing—ribbing should be stretched to meet the garment, not the garment stretched to meet ribbing.
• Broken stitches: Straight stitch was used or thread tension is too tight—switch to stretch stitch or zigzag and loosen tension slightly.
• Ribbing won’t stay folded: Fabric lacks body or recovery—press with steam and consider interfacing the fold line with lightweight tricot fusible or choose firmer ribbing.
• Uneven band width: Ribbing shifted during sewing—press fold firmly before pinning and check fold alignment as you sew.