I have an idea for you. Fractal's first cage was made from pvc piping and black screen. While he was small the mesh is ok. Howver now, he is big. I got the PVC piping but am having trouble finding the tri els for the corners like on his first one. But I will find them. I make a rectangle structure easily with these pop together parts I cut the piping to my desired dimensions. I wrap the screen and literally sew it on to the pipe with 8 pound test fishing line. I pull to the next post and do the same, etc. I leave the smaller front side open. I will have a door made of 2way els and seperate pipes. On the top, I use 1/4 inch mesh wire that holds weight and structure. That way I can rest a ceramic/metal bulb holder right on top. I wire this and a door and cover the edges with plastic cover to avoid pokes or scratches where needed. Fractal liked it alot. I think he misses it since I made him the large round one he's in now. While it is an eye pleaser, I think he liked the square/rectangle.
I will be making the 5ft tall by 3 ft wide one, 2 feet deep and use the round one in the living room as a sun cage only soon. I will use 1/2 inch mesh, but have not decided for sure on the sides as I am learning more about other possible light weight products. That's key for me. Keeping it all light wieght. By the way, I will be making a glass enclosure at the bottom so that I can let bugs go in there so he can hunt and they can't crawl or jump out. Hope this gives you ideas