What a dart does
A dart is a tapered fold sewn into fabric. It removes a small wedge of width so a flat piece can follow a curve, such as the waist or bust. On a pattern, a typical dart appears as two angled stitching lines that meet at a point. The fabric between those lines is folded to the inside of the garment.
Start with a test piece if darts are new to you. A scrap of woven cotton is easy to mark and press, and it lets you see how a change in stitching affects the shape. You will need the pattern markings, a fabric-safe marking tool, pins or clips, matching thread, a needle suited to the fabric and an iron.
Transfer the markings accurately
Before removing the pattern piece, mark both ends of the dart at the fabric edge and the point where its stitching lines meet. Use a marking method that will not show on the finished side; test it on a scrap first. If the fabric shifts easily, mark the stitching lines as well as the point. Check that matching darts on paired pieces sit in corresponding positions.
Fold the fabric with right sides together, bringing the two marks at the edge into alignment. The dart point should lie directly on the fold. Pin across the fold in a few places, checking that the marked lines meet rather than sitting slightly offset. A small error at the edge can change the dart’s angle, so take a moment to smooth the fabric before sewing.
Stitch from the wide end to the point
Begin at the wide end of the dart and sew toward the point. You can secure the stitches at the wide end with a short backstitch, since that end will usually be caught in another seam. Follow the marked line at an even pace. As you approach the point, guide the stitching gradually toward the fold instead of turning sharply into it.
Sew the last few stitches very close to the folded edge, then run the thread tails out beyond the fabric. Avoid backstitching at the point: the extra stitches can leave a small lump. Tie the tails in a gentle knot close to the fabric and trim them, leaving a short length so the knot does not slip loose. Repeat the same sequence for a matching dart.
Press without flattening the shape
First, press along the stitched dart as sewn to settle the stitches. Then place the fabric on the ironing board with the dart pointing in the direction given by the pattern. Waist darts are often pressed toward the center of a garment, while bust darts are often pressed downward, but follow your project’s instructions if they differ.
Lift and lower the iron rather than sliding it across the dart. Press the stitching and the folded fabric without forcing the shaped area completely flat. A rolled towel or a tailor’s ham beneath the fabric can support the curve. Let the piece cool before handling it; this helps the pressed shape stay in place while you continue sewing.
Fix puckers and pointed tips
A pucker at the tip often means the stitching ended too abruptly or the last stitches stopped short of the fold. Remove a few stitches near the point and resew that section with a more gradual taper. If the tip looks bulky, check for backstitching or a tight knot. On lightweight fabric, pull the knot just snug enough to hold without gathering the threads.
If the dart pulls the fabric into an unwanted ridge, compare it with the pattern markings before changing its shape. Uneven folding, inaccurate marks or pressing against the intended direction may be the cause. For a garment that still fits poorly after accurate sewing, test any adjustment on a sample or fitting version first. A smooth dart starts with careful marking, but its final shape is easiest to judge after pressing.
