diy collapsible softbox

Not wanting to spend the money for a professional softbox I decided to go the diy route. I had a few criteria I wanted to meet. I wanted something large, portable, and the ability to use two flashes. I searched out a few other designs to get some ideas, particularly some designs from DIY Photography.net. For the size and shape I based it off this model. It is a 40"x24" face and about 20" deep. The idea would be to construct the box so it could fold into triangles. Initially I was thinking of using some sort of plastic, but in the end went with foam core and gaffers tape for the joints. Each "wall" was actually two pieces to fold into a smaller size. With some simple geometry I figured out the dimensions I need and started to cut the foam core. Once I had the pieces cut, it was time to tape them all together. The outside edge has a long strip of velcro to hold it together. The inside was painted flat white which helps bounce the light since foam core is quite translucent.