If you are worried about predators go with plywood along the bottom 2' of the pen, then chicken wire from there to the top of the pen. Chicks cant get out, chickens cant poke their heads out and risk an aerial attack from hawks, and if predators can't see in it is less likely they will pursue what they cant see. You can get 16 lineal feet out of a sheet of plywood if its cut in half. I used the compressed chip board on my wifes chicken pen and it is holding up just fine. The cost per sheet of that stuff is $7. I used 3 sheets for her 16' x 8' pen. On my 30' x 30' duck pen i used 8 sheets for a grand total of almost $60. It will also help guard against snakes as well. And if it gets really windy out, it acts as a wind barrier as well.