I've been reading Empire of Cotton and this basic question occurred to me. I had always thought of silk as being the most desirable fabric but the book claims that when payment was made in cloth, it was generally cotton that was desired. So why do we have this idea of silk being the most sought-after cloth? And why was it called the silk road if cotton would have been more desirable? Or is the author overstating his thesis?
Firstly, empire of cotton is a fantastic read for the topic and generally one of the most comprehensive books in the area.
Silk was a far more desired material, but cotton was where the large profits could be made quickly. Silk is a highly specialist weave and you'd need what was expensive and secret hardware in order to extract large amounts of the fabric.
Cotton, on the other hand, is cheap and easy to make. Can be made in large quantities quickly and, arguably most importantly, can be transported in raw form as knowledge of how to spin was not secret.
As for the name itself, The Silk Road, it can be traced back to around 50 CE, when the Han emperor made a "gift" of ten thousand rolls of silk to pacify western nomads known as the Xiongnu - silk that would ultimately be transported along the as yet unnamed Silk Road to Persia and the Mediterranean empire of Rome.
Source: Rosen, W. The most powerful Idea in the World: A story of Steam (London: 2010), p.214