Almost everyone has had a piece of clothing shrink in the wash. This is a frustrating experience, especially when the item was expensive or shrunk so much it became unwearable. People sometimes want to shrink their clothes, such as when they lose weight or purchase an item that is too big. Most clothes can be shrunk to some degree. Polyester -- a fabric from which many baseball jerseys are made -- is especially easy to shrink.
Check the label of your jersey to determine its material The chances are good it is either polyester or cotton.
Fill up your washing machine to its lowest water level. Use cold water for polyester, and hot water for cotton.
Place your jersey in the washing machine, and start the wash cycle.
Remove the garment as soon as the wash cycle ends.
Place your jersey in the dryer. Turn it to its highest heat setting, and don't remove the jersey until it is completely dry.