Formal occasion dresses can be tricky to hem. This difficulty may result from the material used for the dresses, which can be filmy and slippery. Such materials, such as chiffon, taffeta, fragile cotton blends and thin silks, add to the beauty of the finished product, but you must handle them with care when sewing to avoid pulls and easily visible hems. Properly hemming a bridesmaid's dress created from one of these fabrics maintains the gown's floaty appearance while providing a tatter-free edge.
Gather your materials. Your choice of thread is crucial to the success of hemming filmy fabrics. Choose a very lightweight nylon thread that either perfectly matches the fabric's colour or is slightly lighter to help make your hem blend with the skirt.
Measure 1/4 inch from the cut edge, which is the bottom of the dress skirt, using a ruler or measuring tape. On the wrong side of the skirt, lightly mark off the 1/4 inch measurement with chalk.
Turn up the edge on the marked line. Pin the edge in place. Pin the fabric gently because delicate fabrics pull easily.
Heat an iron to the lowest setting, as filmy fabrics often are susceptible to heat damage. Test a small unseen patch of fabric. If the fabric doesn't burn, press the turned-up fabric. Pressing is crucial for prepping the hem of slippery or flimsy fabrics; it will help you handle the cloth more easily.
Hand-stitch the hem in place. Use small stitches, close together, for the best wear. This also will protect the dress from the wearer's feet getting caught in gaps in the hem. However, if the dress is shorter, you can make stitches farther apart.
Top-stitching the hem on a machine is an alternative to hand-stitching.