Sheer or clear elastic is often used with clothing to make gathered sleeves, smocking, necklines, hemlines and any other sewing project where the elastic cannot be hidden in folds of the fabric. The elastic is thin and flexible so that it can create stretch in the fabric without causing bulk or visibility. There are a few tricks to sewing sheer elastic to fabric, but once you have the basics down you should be able to sew like a pro.
Cut the elastic to the desired finished length plus one inch. If you want to have a 12-inch gathered arm hole, cut 13 inches of elastic.
Draw a line with tailor's chalk on the wrong side of the fabric where you want to place the elastic. Use a ruler to keep the lines straight and even.
Use a size 75 needle in the sewing machine. Set the machine to make the zigzag stitch.
Pin the elastic to the fabric along the line. Place the end of the elastic ½ an inch beyond the line on each side. Pin the elastic on each end. Divide the measurement in half and pin at the half marks. The fabric should be pinned in four places.
Place the fabric and elastic on the sewing machine. Sew the elastic to the fabric with a zigzag stitch. Make sure the thread sews directly over the fabric. Work slowly and stretch out the elastic as you sew. This will help keep it in line and ensure the elastic stays in the desired place. Remove the fabric from the machine when finished. The elastic should snap back to the original size. Trim the excess elastic from each end of the fabric.