My old unit, a 2010 model FR Grand Surveyor had the back bunk with the bottom bunk as you described with the 45 degree cut off place. We finally just used house-sized double bed flat sheets on the bottom and tucked them in nicely. So much for that with a rambunctious 9 year old g'son sleeping in that bed. You know--the type boy who doesn't just crawl into bed, he gets a running start to see just how far into the lower bunk he can go. Bottom sheet, top sheet, and comforter all wadded up in the far corner. The new unit actually has a lower bunk and a top bunk on one side and a top bunk on the other side. The bottom bunk is rated as a "Queen size" and the two top bunks are rated as "double sized". Yeah, right. Right back to using house sized Queen flat sheets on the bottom bunk and house sized double sheets on the bottom. On the "Queen sized" bed in the front--same story, just use house sized Queen flat sheets and tuck them in nicely. We have a friend who's daughter was selling sheet sets in different sizes and colors as a fund raiser so we looked into these. They are something called "micro-fiber", which is new to me. These sheets actually do not feel so bad and the pricing was well worth buying two sets for each bed just for the camper.