Your two-ply cashmere sweater is so soft that you're probably afraid to put it in the washing machine -- and with good reason. The washing machine can do real damage to delicate cashmere, including shrinkage, stretching or tears. To avoid one of these horrifying accidents, wash your sweater by hand. When it comes to hand washing a cashmere sweater, the method is the same regardless of whether it's a two-ply or a four-ply.
Test your sweater for colorfastness. Dampen a white cloth with warm water, then dab the sweater in a hidden spot. If any dye transfers to the cloth, the sweater isn't colorfast and you'll need to wash it in cold water.
Fill a tub with warm water that measures about 85 degrees Fahrenheit for a colorfast garment. Fill the tub with cold water for a non-colorfast sweater.
Add a capful of mild liquid detergent to the water. Stir the soapy water with your hand until suds form.
Turn the sweater inside out and put it in the water. Submerge the sweater, then swirl it around gently to wash it. Don't squeeze, stretch or rub the sweater.
Let the sweater soak for a few minutes if it's very dirty. If the garment isn't colorfast, don't soak it for long. Soaking makes garments more likely to bleed dye.
Empty the tub and fill it with clean, cool water. Submerge the sweater in the clean water and swirl it around to rinse out the detergent. When suds appear in the water, refill the tub again. Repeat the rinsing process until no soap suds are visible.
Ball the sweater up very loosely. Press it against the edge of the tub to squeeze out excess water. Don't wring water out of the sweater; this can damage it.
Spread out a light-colored bath towel on a flat surface. Place the sweater on the towel.
Smooth the sweater out with your hand. Roll the sweater up in the towel and press down gently to dry it. If this towel gets soaked, continue drying with another towel.
Hang the sweater on a drying rack and let it air dry. Alternatively, if the sweater's care tag allows machine drying, put the garment in the clothes dryer and set it to the tumble-dry cycle.