Jane Quilter,
Unfortunately, I'm highly allergic to rayon, and break out in hives just from touching it, but award-winning quilter Caryl Bryer Fallert-Gentry uses it & it looks stunning! I'm sure you'll have a lovely quilt with that batting! Be sure to post pictures.
Petthefabric,
"Bamboo" is rayon (viscose rayon). The term is used to differentiate from rayon made from eucalyptus or other woods.
Viscose rayon, as a semi-synthetic material, is manufactured to have specific properties. It wrinkles less than cotton (but still does wrinkle), is lighter weight, tends to sleep "cooler" & does have a nice hand.
In response to your question, here is an article about how it is processed:
http://www.differencebetween.net/obj...n-and-viscose/
Here is a video:
http://splash.abc.net.au/home#!/medi...-eco-friendly-
There are more scientific articles out there, but these give the general idea. The process of breaking down the bamboo uses a lot of harsh chemicals. Of course, even just dying fabric is terrible for the environment as it uses a lot of water & in many places ends up contaminating local water sources with the dyestuffs, making it undrinkable. While I personally don't use rayon due to a severe allergy, I think we'll have a much greater impact on the environment by cutting down on the amount of clothes consumers buy in a given year, most of which quickly end up in landfills or are dumped in third world countries by the baleful, destroying local textile industries.