Diaper inserts are generally used as the absorbent part of pocket diapers and are available in different fabrics. While almost all pocket diapers come with at least one insert, some parents find they prefer a different insert based on the fabric or they need to buy extra inserts to double up for naps or overnights. In general, microterry and hemp fabrics are the most commonly used for diaper inserts. Diaper doublers are smaller then inserts and are not made to be the main source of absorbency for a diaper but in addition to what it already has, whether it be a prefold, fitted, pocket, or all-in-one. While doublers aren’t necessary, they add a nice boost of absorbency to a diaper especially if you have a heavy wetter. They’re also great to add for nap time, nighttime, or long car rides.