Zippered Floor Futon Mattress Cover 84" L x 43" W Japanese Floor Mattress Japanese Futon Washable Tatami Mat Cover Beige

I have one of these Costco Roll Out Loungers which is unfortunately out of stock. But I used mine for a few weeks while experimenting with different mattresses and it worked well for me as a 250lb side sleeper (at the time) on top of a Brooklyn Plank mattress. I continue to use it when car-camping on top of a firm camping mattress. I have found that a buckwheat bolster pillow works great for helping support my shoulders when side-sleeping and is more accommodating of different mattresses than a traditional pillow. I really like the JOERRES. A Twin or TwinXL sized topper might be a good choice for travel and it probably would work OK for sleeping with a kid on a King bed but probably not great when on a Queen. Amazon has some similar options if you search for memory foam lounger on their site. If you are going to be moving it frequently, then getting cover (or topper that comes with one) is a good idea since plain foam toppers will quickly start to break down from constant folding/unfolding and rubbing. They also attract dust and dirt and are nearly impossible to clean once soiled.