Fabric and batting made from an 80 percent cotton and 20 percent polyester blend offers the breathable quality of cotton and the reduced shrinkage of polyester. While fabric and batting blends made from cotton and polyester do not shrink as much as pure cotton fabric, you can shrink them. Expect the 80 percent cotton and 20 percent polyester fabric or batting to shrink about 3 percent. The key to shrinking the cotton/polyester blend is adding a combination of heat and moisture.
Fill the washbasin about half full with warm water. Add more water if it does not look like enough to cover the cotton/polyester fabric or batting you are shrinking.
Push the cotton/polyester fabric or batting under the warm water. Hold it under the water until it absorbs enough water to make it heavy and the fabric or batting stays submerged when you release it. Let the cotton/polyester blend item soak at least 15 minutes. Add more warm water if it begins to feel cold.
Drain the water out of the basin. Take the cotton/polyester item out of the washbasin and lay it out flat on the bath towel. Roll up the towel and the cotton/polyester item together from one end of the towel. Push down on the rolled up towel to squeeze out excess water from the cotton/polyester item inside it.
Place the 80 percent cotton and 20 percent polyester item in the dryer when all the excess water has been squeezed out. Run the dryer on the cool, gentle setting until the cotton/polyester blend item is dry.
Remove the cotton/polyester blend from the dryer as soon as it stops. This is especially important if you are drying fabric rather than batting because fabric will wrinkle.