The towel seems to be made from a mixture out of cotton, spandex and nylon. Without a picture with a higher resolution I can only guess but I think its probably 82% cotton, 13% nylon and 5% spandex. Hope that helps.
If this wasnt the information you were looking for: I always had good results when using Windex to clean my mirrow. Also helps to soack that sticker with it and than use a sharp tool for example a razor blade to get it off.