Cashmere is a beautiful and delicate fabric that requires special care. Re-sizing delicate cashmere clothing can be challenging. The only reliable way to shrink most clothing is by exposing it to high water temperatures in a washing machine and intense heat in a clothes dryer. However, this may compromise the structure of cashmere, distorting the garment's shape and cause it to pill. Consider the risk carefully before attempting to shrink a cashmere sweater.
Fill a sink or bucket with warm water. If you wish to also clean the sweater, pour a cap full of baby shampoo into the water and swirl it around until it is fully dissolved.
Immerse the sweater in the water and let it sit for around ten minutes. This will allow the fibers to become fully saturated.
Remove the garment from the sink and use a towel to absorb excess water. Do not wring or twist the sweater, as this may cause it to become misshapen.
Place the sweater in a clothes dryer and select a permanent press setting.
Allow the sweater to dry fully in the dryer. Then try it on. If the sweater is still too large, put it back in the dryer on a high heat setting for several more minutes.