Never, never clean or wash pillow covers if they are actually the furniture covering. Zippers are meant only to aid in achieving a good fit. Wool fiver-filled comforters are prone to extreme shrinkage. Never wash them and always inform your drycleaner of the wool filling. Otherwise, what is known as depreciation comes into play.
Depreciation is the difference between what it cost new versus what an item is worth now.
That is why if your auto becomes a total loss, the insurance company only pays you on the depreciated value. The insurance company looks up the model in a book, adjusts for mileage, and pays that amount. The listed years represent the item's life expectancy. Solvent Recycling Drycleaners don't get the credit that they deserve for protecting the environment. We were recycling before the term became popular.