Combed cotton shrinks when dried in a hot dryer due to the natural cotton fibers contracting from the application of heat. The amount of shrinkage varies, but is less pronounced in garments pre-shrunk during the manufacturing process.
To prevent shrinkage and maintain the best appearance of the clothing, wash cotton items in cold water and hang them outdoors to dry on a laundry line. If line drying is not possible, hang the clothing in a bathroom or place it in a dryer on low heat. Removing cotton clothing from the dryer while it is still damp also helps minimize shrinkage.