Professional launderers know that wool is sensitive. If you’re not careful and carelessly throw clothes made of high-quality, pure wool into the washing machine with other garments, it’s not uncommon to end up with a child’s sweater. But what is actually the reason for this? The wool fibers are surrounded by a layer of dandruff that snags during the spin cycle and causes the garment to shrink. Care labels make it clear which sweaters may and which may not be put in the washing machine.