Transform your garment sewing by using a ham to press curves and darts! A tailor's ham or dressmaker's ham is a tightly stuffed pillow used as a curved mold when pressing curved areas of clothing, such as darts, sleeves, cuffs, collars, or waistlines. Pressing on a curved form allows a garment better to fit body contours. To accommodate tapering or garments of different sizes, it has roughly the shape of a ham.