Turn a plain and ordinary shirt into a fashionable top with just a simple change of neckline. A boat neck shirt has a wider neckline than most shirts and can be customized to reveal just a little glimpse of shoulder with a narrow neckline; or make a dramatic change with a deep, widened neck that shows off a bit more skin. Complete the transformation by finishing the new neckline with a binding trim, or create an edgy-looking shirt with an unfinished, ragged neck.
Lay the shirt on a clean, flat surface. Find the left shoulder seam and measure 1 inch inward. Make a small mark with tailor's chalk. (You can use a pencil or fabric pen if you do not have tailor's chalk). Find the right shoulder seam and measure 1 inch inward. Make another mark. This is the new width for the shirt's boat neck neckline.
Find the center of the neckline and measure downward 1 inch. Make a mark. To make a lower neckline, measure down farther.
Connect the marks by drawing a curved line from the mark at the left shoulder, to the mark at the center, and to the mark at the right shoulder.
Measure the distance from the left shoulder seam, across the back of the new neckline to the right shoulder seam. Cut a piece of the 1/2-inch-wide binding tape.
Lay one end of the tape at the left shoulder seam and pin it to the shirt. Add another pin at the edge of the new, wider neckline. Open the tape and slide the back of the neckline in between the two layers of the tape. Pin it in place. Pin the other end of the tape at the right shoulder seam. Sew the tape in place.
Measure the length of the front of the neckline. Cut a piece of binding tape to this length.
Slide the front of the neckline in between the two layers of the tape and insert pins to keep it in place. Sew along the tape to attach it to the shirt.
You can make your own binding strips for the shirt for a completely customized neckline. Cut one strip of fabric for the back of the neckline and one for the front, in the same way you cut the binding tape for the shirt. Make each piece 1 1/2 inches wide. Fold over 1/4-inch of fabric along each long edge of each strip and iron the folds flat. Fold each strip in half lengthwise and iron along the crease. You now have your own binding tape to add to the shirt.