Yes. If you have purchased diapers with synthetic fabrics, you need only pre-wash once to remove shipping dust etc. before using them on your baby. Synthetic fabrics include PUL, TPU, microfiber, fleece, nylon, athletic wicking fabrics, suede cloth, minky and/or zorb.
Natural Fabrics – Bamboo
If you have purchased diapers that are made in any part with bamboo or come with bamboo liners, you can get away with just one initial wash before use (I’m lazy), but be aware that bamboo becomes more absorbent over time and with multiple washings. So if you are getting leaks, keep in mind that your bamboo may need more washings before reaching maximum absorbency (between 3-10 washings). If you want to play it safe, then pre-wash bamboo fabrics 3-5 times before use.
Natural Fabrics – Cotton Prefolds, hemp, etc.
For organic cotton, most often used in prefold type diapers like the Bummis prefolds, you will need to do 3-5 pre-washes in hot water before they are ready for use. Since natural fabrics are not bleached you will need to do the pre-washes to flush out all the natural oils that would affect proper absorbency if used right away.
Pre-washing your diapers also helps to bulk them up and puff them up making them nicely quilted and soft. You should expect approximately 25% shrinkage when your pre-washes are complete.
Natural Fabrics – Wool
Wool does not need to be pre-washed, however, if it has not been lanolized prior to you receiving it, then it needs to be lanolized before use.
Covers only need one wash before use.
NOTE: Pre-washing means washing in a recommended cloth safe detergent AND drying the diapers. In other words, one pre-wash includes a wash and a dry (whether you air dry or dry in the dryer does not matter).