I've just returned from a holiday in Ecuador. I'd packed a roll in my suitcase, and found it advisable to keep 12 squares or so folded and contained in a ziplock bag. That was thin enough to keep in a back pocket.

I also consider toilet paper to be one of the myriad uses for a bandanna. I try to carry at least one 35" silk, again folded into a back pocket. In extremis that can be cut into 49 5-inch squares.