Wool is elastic and durable, as long it is treated in a manner appropriate to the garment. Rustic wool and alpaca are tough and resilient. Cashmere is more delicate. If you take care of it, your Invisible World sweater will last you many years.

A wool garment should never be washed in warm or hot water, or in the washing machine. Unless you have been accidentally exposed to nuclear radiation and find yourself getting smaller every hour like The Incredible Shrinking Man, you will truly regret the irreversible felting process that you have unleashed on your garment. Shrinking of things is better left to the Jivaro Indians of the northwest Amazon.

A wool sweater or knit jacket should never be hung on a hanger or crucified on the back of a chair. This is called “punishing your sweater for something it didn’t do.”

Never hang a wet sweater up to dry. This is called “torturing your sweater for information it cannot reveal.”

To hand-wash a sweater you should wash it in cold water with a mild detergent like Woolite or a good shampoo, gently kneading and squeezing the garment without twisting or wringing it. Adding hair conditioner or fabric softener will make your sweater silkier. After rinsing, you should gently squeeze out the water and lay the sweater flat on a towel to dry.

Although it is virtually impossible to systematically shrink a sweater to fit, it is possible to stretch out a sweater a little bit to just the right size. This is called blocking the sweater. To do this the sweater should be washed or at least well soaked. Then, after squeezing out the water, and laying it on a towel, the sweater is gently and evenly pulled out to the dimensions desired. The sweater should then be weighted with clean heavy objects until it is dry. It will then retain its new shape.