Washing and drying a hat may seem like a simple enough task until you begin the process. Some hats, such as knit ski caps, can be washed and dried just as any other knit item is washed. Simply follow the directions on the tag. Other hats, such as formal top hats, cannot be washed and should be spot cleaned with a damp cloth when dirty. However, one of the most popular hats of all--the baseball cap--can be washed and dried without damaging the cap, but only if you follow specific instructions.

Prior to 1983, baseball caps were made with a piece of cardboard in the brim to give it a hardened bill that could be shaped once it was purchased. Therefore, putting it in any sort of water will ruin the hat. Also, hats made prior to 1983 were not as durable in regard to colored dyes and materials. For these reasons, hats manufactured prior to 1983 require special care in order to wash them.

First, do a color test. Do the test with a mild soap and some warm water in an inconspicuous area of the hat so that if the color runs or lightens it will not be noticeable. Allow the area to dry and examine the results. Treat the worst stains and the sweatband by hand with a toothbrush to scrub the affected areas, concentrating mostly on the sweat band. Allow the hat to air dry and never place it in the dryer.

To find out if your baseball cap was made before or after 1983, look at the tag on the inside of the cap. If there is no tag, then odds are it was made in 1983 or before. If you think the hat is newer, but there is no tag for proof, you may want to take precautions and simply avoid washing the hat in a washing machine.

In 1983, the cardboard in baseball hats was replaced with plastic, making them more durable for the washing machine. Baseball caps made after 1983 are simple to wash. The only type of baseball cap made after 1983 that you want to avoid washing in a machine is a wool cap, because it will shrink.

For any other baseball cap, simply apply a pre-stain treatment to areas of the hat and throw it in the wash with the rest of your clothes. Once the washing cycle has completed, pull the hat out and let it air dry anywhere. Once the hat is dry, reshape the brim, if needed. You can also buy a plastic hat cage for baseball hats that will help them to keep the form with which you are comfortable.

Washing a wool baseball hat requires some extra work because it must be washed by hand using a very mild soap. Washing should concentrate solely on the grime in the sweatband of the hat because rubbing the fibers of the wool on the hat itself can ruin the appearance of the hat. Wool is also prone to shrinking easily. Therefore, it is necessary to hand wash your wool baseball cap in cold water rather than hot or warm water. To dry the hat, place it over a coffee can or some other head-like form to keep its shape. Most importantly, never put your wool hat in the washer or the dryer.

Certain other types of hats may also become dirty and need cleaning. If you have a felt hat, you should not wash the hat in a washing machine because it can damage the felt. Instead, use a stiff brush with natural bristles to brush dirt or grime off the hat, moving the brush in the direction of the weave. If your hat accidentally gets wet from inclement weather, you can use this same brush, brushing in the direction of the weave, to dry the hat. If a felt hat becomes too wet, it will lose its shape.

When washing an angora hat, hand wash it in cold water and then roll the hat up in clean towel. Use tissue to stuff the hat so it is in the proper shape. Brush the hair of the angora so it is all going in the same direction, then let the hat air-dry.

Cotton or casual hats can be washed on the gentle cycle on your washing machine and air-dried.

Top hats can be spot cleaned using a soft damp cloth with gentle dish soap. If they become very dirty, they may need to be dry cleaned.