Something i have used if you can hang it freely with nothing right behind it is a couple pieces of old carpet one thickness will stop arrows from most bows two to four should stop most everything before the fletches. Just pick it up from a carpet installer after he tares it out of some ones house. You can also use it stacked and bound or stuffed in burlap as a target. My favorite is plastic wrap from a furniture store stuffed in burlap the plastic is free and burlap is fairly cheep at most fabric stores