I agree with others about avoiding bareback pads with stirrups at all cost. Not only do they concentrate all that pressure at one tiny spot on the horse's spine, but with no rigid tree to keep the pad in place, if you get off balance, the pad will easily slide all the way to the side...allowing you to fall and possibly get drug since feet don't easily come out of those cheapo stirrups they put on them.
When I ride bareback, 90% of the time I use my bareback pad (homemade out of an old 3/4" felt saddle pad) to soften the pressure of my bony butt and also protect my own butt from sweat and hair. I'm not a fan of the brown butt look LOL.
Forgive his drippy appearance, we got caught in a rainstorm.