Excerpted from the Bijou washing and care page: When you buy a new woven wrap or ring sling, it comes to you in "loom state." It was woven on a loom and then finished, but it has not yet been washed and IS NOT YET READY TO BE WORN.
The fabric needs to be washed to set the weave. Wearing before a wash could cause thread shifting. Do not use bleach, fabric softener, powdered detergent, or detergent with optical brighteners.
SHRINKAGE: During its first bath your wrap or ring sling will shrink, which is normal. We cut the fabric so that it will shrink to the size that you ordered (within tolerances).
WASH: Wash before wearing the first time. Wash gently alone in cold water, no spin, with liquid detergent that does not contain optical brighteners. No bleach, no fabric softener. For ring slings, putting the rings in an old sock and/or putting the whole thing in a pillowcase is a good idea.
DRY: You may tumble dry low heat. Hanging dry is also great, especially for Tencel, which dries very quickly and doesn't like heat. If you tug the fabric as it hangs, some blends will hang dry with no wrinkles.
IRON: For all-cotton blends, steam iron with medium heat if you like, which helps break in the fabric even more. The other fiber blends should only be ironed on warm (one dot) if necessary. Refer to the care tag for instructions specific to your fiber blend.