Elkrun , you are corect. It is called expanded metal. Earlier in the season I was building some safari racks for my vehical and I could not for the life of me find it any where, Home Depot , Lowes, Mclendons, you name it they didnt have it.

Finally I found out what it was(expanded metal) and found tons of metal shop in the Renton/Auburn area.
Try Grating Pacific in southcenter, I had mine cut for a small fee. They have it in all thickness and styles.

http://www.gratingpacific.com/