thumb|Hem detail with inscriptions (Saint-John in Crucifixion, [[Vicino da Ferrara, 1469–70)]]
In sewing, a hem is a garment finishing method in which the edge of a piece of cloth is folded and sewn to prevent unravelling of the fabric and adjust the length of the piece in garments, such as at the end of the sleeve or the bottom of the garment.
Methods
thumb|A [[presser foot on a home sewing machine includes measurement markings on the plate beneath the foot for easier hemming. Shown are measurements in fractions of an inch (above) and in millimetres (below).]]
There are many different styles of hems of varying complexities. The most common hem folds up a cut edge, folds it up again, and then sew it down. The style of hemming thus completely encloses the cut edge in cloth, so that it cannot unravel. Other hem styles use fewer folds. One of the simplest hems encloses the edge of cloth with a stitch without any folds at all, using a method called an overcast stitch, although an overcast stitch may be used to finish a folded "plain hem" as well.
There are even hems that do not call for sewing, instead using iron-on materials, netting, plastic clips, or other fasteners. These threadless hems are not common, and are often used only on a temporary basis.
The hem may be sewn down with a line of invisible stitches or blind stitch, or sewn down by a sewing machine. The term hem is also extended to other cloth treatments that prevent unraveling. Hems can be serged (see serger), hand rolled and then sewn down with tiny stitches (still seen as a high-class finish to handkerchiefs), pinked with pinking shears, piped, covered with binding (this is known as a Hong Kong finish), or made with many other inventive treatments.
Most haute couture hems are sewn by hand. Decorative embroidery embellishment is sometimes referred to as a hem-stitch design.
Types of hems and hem stitches
A variety of hem types exist because there are so many different fabric types and garment styles. Common types of hems include:
- Double-folded hem
- Overlocked and folded hem
- Rolled hem
- Bias tape hem
- Blind hem
Hems of different depths (which includes the seam allowance) may have a particular style to achieve, which requires more or less fabric depending upon the style. A handkerchief-style edge requires a hem allowance of . A typical skirt or pant hem may be . An interface fabric sewn to the fabric in the hem has a useful function in some hem styles. A bias strip is sometimes used as a hem interface. This adds fullness to the finished garment and reduce wrinkling.
The hem stitches that are commonly used for hand-sewn hems include: pick stitch; catch stitch (also called a herringbone stitch); slip stitch; and blind stitch.