Hand-washing is the gentlest of cleaning methods and, when done correctly, can add years to the life of even the most delicate fabrics. Sweaters are best when hand-washed, though it is important to be especially careful with wool and cashmere, because the fibers weaken and stretch out of shape. To prevent this, handle wet garments carefully, never wring or twist, and try Martha's blocking method to restore them to their original shape after washing.
2. Swish the sweater in cool, sudsy water, gently squeezing the suds through. Let soak for about three minutes, then drain the water. Run clean water into the basin to rinse the sweater until the water runs clear. Carefully press out excess water from the sweater.
3. Taking care to support the weight of the wet garment, lift the sweater onto a dry towel. Pat the sweater into shape, and roll it up in the towel, pressing to remove excess water. If the sweater is heavy, you may want to repeat this step with a second towel.
4. Lay the sweater on a dry towel, and reshape, referring to the measurements you recorded earlier. If a sleeve is too long, carefully pull it out widthwise to adjust the length. Allow the sweater to air-dry on the towel for several hours.
5. Once the sweater is dry, fold it carefully by laying it face-down, folding one sleeve straight across toward the opposite shoulder, then the other sleeve. Fold one side in so the corner of the sleeve is at the center of the sweater, then repeat with the other side. Fold the bottom up once. Never hang a sweater, as it will stretch out of shape.