The material needed to be as lightweight as possible, strong and durable but not too expensive. PVC is way too weak and wouldn't be able to widthstand the weight of the tiles. The material that was chosen was metal poles. This allowed the whole box to be transported more easily.
Plastic sheets were chosen to weigh down the bag. These plastic sheets are quite thin but heavy, allowing for a sleek, flush look and easier transportation and use.
Putting It Together
Top Frame
Bottom Frame with Metal sheet
Assembly
Final product, with connection to burner