Of course nylon, satin, slinky material is the best, but if some guys love their cotton panties, more power to them. As long as they are panties! I think there are a lot of complex factors that inform one's preferences, including first experiences, psychological ideals, certain vectors of kink, etc. With that being said, however, I wonder about the fact that when I was growing up and getting into crossdressing, and panties specifically, nylon was the predominant fabric used, even for little girls and teens. Now it is nearly impossible to find nylon panties for girls, with the "health" concerns being the driving factor (albeit this is perhaps just speculative from the bastions of healthcare). With this as a standard, some women just continue wearing cotton panties into adulthood, it being the type that they have grown up with and are comfortable with. If I were 11 years old now, and tried on my sister's panties for the first time, undoubtedly they would be cotton. Would this be my bonding experience, and thusly would I be only about cotton panties? Don't know. But beyond this, I feel that nylon, polyester satin, etc. (the sensual fabrics), are defacto SENSUAL. The smoothness and suppleness is a body sensation, and its tactile stimulation occurs regardless of other psychology. You get turned on because it feels good. When I was a kid, my own BVD's were already cotton, and I knew how that felt. Meh. But after trying on my Mom's Vanity Fair bikini panties for the first time, I was turned on. Yet after that, having already identified panties with being turned on, I used to fold the wet wash rag when I was in the shower into a triangle and place in against my crotch, pretending that it was a pantry, getting turned on. I had already identified "panty" with those feelings, not simply the tactile sensations. So it can be a lot about the head, which, of course, is just a big bag of unknowable... stuff.