How To Shrink A Cotton Shirt. Dry the shirt on HIGH HEAT in the dryer. Using the hottest water setting wash the shirt by itself.
Simply heat up a pot of water then shut off the stove as soon as it reaches a boil. Remove the shirt from the pot when the water has cooled. Most cotton shirts not pre-shrunk will only shrink about 20 from its original size.
Also it depends on whats the size of the shirt you want to shrink.
Use warm water if the fabric allows it and a mild detergent. It may be ok to use hot and warm water if the shirt you are trying to shrink is white but I am uncertain if it will change the brightness of your white. Cotton clothes can sometimes shrink but if you take care quality cotton will stay like new for a lot longer. Check periodically throughout the drying cycle to make sure you dont over-shrink the garment 4.