you can buy more background here...
https://marshalldrygoods.com/shop/de...-white-on-whit
he only has the 108" right now..you could buy 3 yards and do backing and your block..or keep checking back, he has the 44" a lot and should restock. They have always been great when I;ve called them..sometimes they have just a few yards of what you need and don't put it on the site. Never hurts to ask.