The tailors ham from Prym is a practical aid, which no sewing and craft work fan should be without. Folds in fabric necklines, waist bands, cuffs, darts or curving seams can quite simply be ironed out. Side seams and seam allowances no longer push through. 
 
Doubly useful: The cotton side is suitable for smooth fabrics and higher temperature settings, the checked wool side for lower temperatures and more voluminous materials.