I put a small mat on the playpen for the 1 year old, but when my 3.5 year old arrived, her Mom told me she naps, and I just assumed a child that age doesn't nap anymore, so I wasn't ready. I took the mat out of another playpen and put it on the floor for her with a pillow and blanket. I would love to find fitted sheets for my pack n plays if anyone knows where to get them.