The flounce hem on women's dresses and skirts has been popular for centuries. A flounce hem is a very wide ruffle at the bottom of a hem or skirt. It is far wider than the 2-3 inch (5-7 centimeter) ruffle hem often seen.
The word "flounce" is even old. It appears as early as Middle English as the word frounce and comes from the Old French word fronce, all meaning "pleat." Indeed, a flounce is pleated on the upper part, then sewn on to the garment. A flounce hem adds movement and interest as well as ornamentation to a garment. It is considered a dressy addition to a skirt or dress, although lace or chiffon flounce are popular on upscale lingerie as well.
Paintings of women as far back as the middle 1500s show a flounce hem on skirts or fine linen sleeves. The frilled sleeve so popular in the late 1600s and early 1700s is a type of flounce as well. Flounce were extremely popular in the mid-1800s, after large hoop skirts made their debut. A hem 15 to 20 inches (38-50 centimeters) wide was not unusual, especially on a young belle's ball gown. These flounces moved and fluttered as she danced, giving a pleasing effect.
Making a flounce hem requires some skill on the part of the sewer. The material is generally cut in a long rectangle, to the desired width, including a 1/4-inch (6.3 millimeters) seam allowance. From here, there are two ways to make a flounce hem. The sewer can sew a long basting down the length of the fabric, within the seam allowance. The bobbin thread is then gently pulled out of the material. The fabric will begin to pucker and pleat and the sewer is left with a pre-gathered length of material, ready to be sewn on to the main garment.
A second way to make a flounce hem is to cut the fabric, again to the desired width, and with right sides of the fabric together, pleat the fabric by hand as it is sewn on to the garment. This is extremely difficult, because it is so hard to get the pleats spaced exactly right, and sewn flat.
Some fabric stores sell pre-pleated chiffon or other fabrics that have been basted on to trim tape, and the sewer merely needs to attach the tape to the garment. This is by far the easiest way to accomplish a nice hem.
A sewer interested in learning the technique is best served by practicing the various methods on scrap material before attempting a full garment.