You should wash all your nappies and accessories at least once before you use them on your baby. This is to remove any factory, storage or transport residue.
While you can start using them after one wash, natural fibres will require at least 8 washes before they achieve their maximum absorbency. This includes Bamboo & Hemp inserts, Fitted nappies and Hemp flats. It is a good idea to keep your new inserts in your laundry area and include them with other household washing to help achieve the washing target before use.