Cashmere responds best to gentle hand-washing. Clean your sweater in a sink or basin using lukewarm water. Our experts recommend Soak Laundry Rinse, a no-rinse detergent, or Eucalan Delicate Wash.

Pilling—those little balls ... for removing bug larva." If the problem is severe, quarantine your sweaters in plastic bags until you can wash them thoroughly. Taking your precious cashmere ...