That's an inventive way to build a light box!
Thanks. All of the DIY instructions seem to cost around $20, and some take quite a bit of work. I figured no sense in spending time and effort, and money, on something I might never use again, so K.I.S.S., and cheap. I did go to a glass company 10 or so years ago and asked if I could go thru the scrap barrel. When they heard what I wanted it for, they cut me two pieces out of a new pane of glass, and didn't charge a cent. Been saving that for a light box build, and was going to use one of those, until I thought of the microwave door. I think I've got aluminum foil, and if not, got white paint. Got duct tape, Titebond II, and a lot of cardboard I need to get rid of. Got some old pant legs and shirts I will cut up, then glue to the sides, which will strengthen it. And I regularly carry two small flashlights (led, with 3 AAA batteries, plenty bright, and about $1 each ). I have found that cardboard, reinforced with cloth, can make a surprisingly sturdy build, for one time projects, such as this.