Cotton is a fiber (from the cotton plant). Flannel is a finish or weave. Hence you can have flannel wool as well as cotton flannel - i.e wool made with flannel finish or cotton made with flannel finish. Hope this helops.
A very memorable song from Joni Mitchell that featured the line They paved paradise and put up a parking lot.. This best described places I remember growing up in Bloomington, MN in my teens where numerous places were torn down, most notably a restaurant I frequented that was replaced with a Park and Ride lot.
Mitchell (from a 1996 interview with the Los Angeles Times): I wrote 'Big Yellow Taxi' on my first trip to Hawaii. I took a taxi to the hotel and when I woke up the next morning, I threw back the curtains and saw these beautiful green mountains in the distance. Then, I looked down and there was a parking lot as far as the eye could see, and it broke my heart... this blight on paradise. That's when I sat down and wrote the song..