working on building one now out of layered cardboard boxes. slow going 3/4 done now. after i get the height i want and it is 20 deep I will cut matching peices of ply wood for top and bottom then use an old ratchet strap to compress it till i have good arrow stop and easy removal. I tried a morrel yellow jacket block target a few years ago. It was very hard to remove arrows and it fell apart rather quickly. the two faces of the target are a nice foam type matterial but inside there is like 3 or 4 diff materials..