prewash

Pre-Wash before first use
When you first get your diapers, it is very important to do a pre-wash on them before the first use. If you choose a natural fiber, such as hemp, bamboo or unbleached cotton, you should wash them 4-5 times in hot water using a small amount of detergent. This helps to remove the natural oils in the fibers and allows for maximum absorbency. We advise 7-8 pre-washes for hemp for maximum absorbency. Make sure to wash bamboo and hemp diapers separately from other types of diapers because the oils in them can run into the other fibers. 
If you opted for something else, like polyurethane laminate, or micro fleece put them through two cycles on warm or hot with a small amount of detergent and dry.