Hi, I agree with Gayle. No one in my family has a butt. Since I have an autoimmune disease that took the little bit of muscle I had in that area I have trouble sitting on any hard surface. I always pack one of those blow up rings as well as a pillow to use on a metal folding chair. I also take a plastic box meant to hold small parts etc. that brings my non sewing foot up to the same level as the foot pedal so my legs are alligned. It really helps when participating in a sewing marathon.
I am going on retreat starting next thursday through sunday. I don't have a thing packed yet.
Have a blast and be sure and take your favorite snack.