I began making them and gave up finally settling on twin fitted sheets for the electric bench and 1 each for the smaller two. I discovered that fitting the corners on the small ones from the top, then wrapping them 3 times fits perfectly. Tuck in the excess width and voila'. We slide a strip of non-slip rubber mat beneath each which keeps them from sliding off. We leave the 2 smaller cushions home and make the bed with twin sheets, open in center making it easier to get in and out, and reach cabinets. I just roll them to the foot during the day, leaving the fitted sheets, raise the bench for day use. Works great! Linda and Grady 2006 Adveturous
When using fitted sheets, elastic "sheet suspenders" or "bed bands" available at Amazon, Walmart, Target etc help to keep the sheets from popping off. You can also make do-it-yourself versions, use strips of elastic and safety pins, fastening them on the underside of the corners of the sheets.