Zaino Bros' recommends using only Large Bath size 100% Made in USA White Cotton towels with all of our products. Cotton T-shirts are too small for polish removal and not as absorbent or fluffy as towels and most contain polyester. We have found that certain towels; especially those manufactured abroad, although they say 100% cotton. They are not; they include a blend of polyester and nylon that will definitely scratch and leave swirl marks in your paint finish. The rule of thumb is to use high quality Brand Name large bath towels (Cannon or Fieldcrest) that say 100% cotton and made in the USA. Towels sold in bags in Auto Stores are not 100% cotton. Look carefully on the bag it will probably say made in Pakistan or Bangladesh or other foreign country. Do not use these towels. They will cause swirl marks and scratches on the paint surface. Always, remove the stitching around the towel prior to use. Bargain store polish applicators also contain polyester and nylon fibers and are not to be used. Also, when washing your towels, please do not use any type of fabric softeners. Always use White towels. Do not use Colored Towels they contain dyes.