I use Sharpie permanent marker in black for the drawing. (Have not tried any other colors) Surprisingly they do not bleed on the hide. I do not believe I would use any rawhide drum inside of a sweat lodge. I have been to native american drumming events and seen them hold the drums near a fire to keep the moisture out and the sound right. A sweat lodge would likely cause a very slow and poor sound if the moisture was high. I would put the drummer on the outside of the lodge near the fire that supply's the hot rocks. There may be some ceremonial purpose for having the drummer inside the lodge but I am not aware of it.