• You don't need a sheet. Most play yard mattresses, which are thin, can be cleaned, and the bassinet is safer without this extra piece of material, in which a baby could become entrapped. But if you do use one, make sure it is tight-fitting and specifically made for the mattress or bassinet insert on your model. Never use a sheet made for a crib mattress or twin or other size bed.
Nice to keep baby out of trouble at home. Once he became mobile we had to do an "upgrade" as we noticed he was starting to hit his head on the X shaped metal bars. We tried some alternatives but the best so far was wrapping the metal bars with pool noodles (see picture). You'll need 8 pool noodles and some cuts (buy some extra in case you mess up). Use 2/3 of a pool noodle to wrap the internal bars and the remaining 1/3 to wrap half of the external bar. The pieces will also need a longitudinal cut along the length to fit the bar in. You'll also need some small cuts in the middle of the longer piece to fit the center rivet, where the mesh is attached to the bars. We got the pool noodles at the dollar store nearby for less than $10 and since ... full review