I had a similar situation and great success with "diamond steel mesh" from Lowe's.
It comes in sections 8ft long by 27 inches wide for about $8 per section. It's used in masonry... probably concrete reinforcement. It's sturdy (about 1/8 thick), and a small mesh. Very strong, but won't rust. Top and bottom edges are smooth along the 8 ft. Cuts easily with snips.
I built a circular exercise area for our 2 ducks out of this and steel U-posts, using zip-ties to hold the mesh in place. 2 sheets high makes the pen about 45 inches tall (with overlap).
The gate was the best part, though. I found that if I rip through 1 side of a 3/4 inch pvc pipe, I can slide it over the edges of the mesh. The pvc is cheap, easy to work with and adds a lot of rigid strength to the gate. Also eliminates any sharp edges.
Don't know exactly what kind of pen you need, but I can testify that this is the strongest and easiest stuff to work with that I've found.
Quote:Hey stormdog i also use that also for some of just small cages it is called metal lath used for stucco and rock laying and it is usually found in the lumber department in lowe's at the concrete its about the right height for small cages like rabbits and such great stuff hope this helps someone