Prefold diapers can be pinned, folded or used to line other diapers to add more protection. They are in the shape of a rectangle with an absorbent pad already lined to suit your baby's needs. If using a pre-folded diaper, you will need a separate waterproof cover. Prefold cloth diapers are popular among many moms and dads because they are the most inexpensive cloth diaper option and dry quickly. Your baby may also not need as many different sizes as they grow and change - and outgrown diapers can then be used as diaper inserts, burping rags or even cleaning cloths. However, folding a prefold diaper does generally take some practice, and prefold cloth diapers always require a separate diaper cover.