I have been wearing silk shirts 99% of the time I leave the house for decades because I just love the feel of them. For this reason, I do NOT wear silk underwear ;~)) About 5 years ago, I found some "bamboo" viscose shirts that felt every bit as good as any silk (including Versace) that I had ever owned. For me though, the biggest advantage to the "bamboo" shirts is they are VERY easy to care for (washing machine, hang to dry, no wrinkles). This means no dry cleaning bills or trips to the store ;~)) This also means the shirt does not get wrinkled from a trip in the car to the restaurant or elsewhere ;~))
Now as far as I understand it, they can not call it "bamboo" (this shirt is made from bamboo fiber or viscose) because if it were to be called that, it would need to be made from strands of the the bamboo, and it is not (which is why I had been putting bamboo in quotes - I believe this is a FTC rule). The pulp is extracted from the bamboo and made into viscose fiber, which is then made into a fabric. Rayon is a marketing title for viscose best I know. And not all viscose (rayon) is made from bamboo. Other woods can and are made into viscose fiber as well. Also, not all viscose is going to be created equal. Some is going to be better than others, just like cotton or any other fabric material.
The article that admin M@ linked to certainly raises concerns and although the best practices could/should be followed, the price of producing the products will trump those practices in most cases until they are forced through laws/regulations to implement such best practices.
Long and short is, for me, viscose fiber has come a long way and I have been buying more and more shirts made of that material (I have about a dozen whereas I have about 100 silks). We also have bamboo fiber bed sheets and they are delightful as well.
