Hey JG, the screen is made of good old fashioned baling wire. It is pretty rigid, yet flexible enough to string back and forth to create a netting. It comes wrapped up in an oiled paper to prevent it from rusting, so it is a bit messy to work with. Overall it created a nice net that I decided would be best as 3 inch x 3 inch. Here are some additional pics.

Regarding Pic 2, that is the top and bottom of the PVC frame that I put together ahead of time. You'll notice it in the other pics when you look closely. Most everything else in the frame is just 1/2 inch PVC pipe cut to length.