For those of you who might be thinking chicken wire is OK to do your run? Think again......as in don't do it! This is our neighbor's run. The main wire is chain link, but they put chicken wire over it to keep the wild birds out. Look close and you can see the damage some varmint did to the chicken wire trying to get in. I suspect a 100 pound hog could wriggle under that the way the varmint left if. If not for the chain link backing, those birds were graveyard dead. If you don't do the chain link and double it with chicken wire like they did, my preference is 14 gauge welded wire. Pick the size to repel your smallest predator. 2" x 4" might do it for the larger ones........1" x 2" for most..........1/2" x 1" for the nasty little guys. This stuff is essentially sold by the pound so the cost will be commensurate with the size you buy. The smallest grid being the most expensive. 14 gauge is way heavier and larger than most 1/2" hardware cloth, which might be 19 gauge at best. HC would be great as the doubler over the chain link. Main advantage of the chain link, aside from it being heavy and durable, is you can probably find it used and in tall heights like this one is, which is 8 feet.