Originally, it was stoft who pointed out that the shininess of cell phones backs when using the foldup spec can contribute to reflections. This is quite true. After helping 60+ people make foldup specs in the past month, I needed a quick fix.
Going to a stationary store with an infragram, you can quickly tell if black paper is really black. To compare, I brought a recent foldup that really is black, as well as an older discontinued foldup that used paper that was reflective in infrared.
Satisfied that my black paper would work, I took a hole punch and quickly
It masks the back of the phone but leaves room for the lens. It's fastest it you cut the paper into strips, then punch holes in a line, then snip them into squares, about 1" square is enough to mask the large DVD window of the foldup spec. You can affix it either to the foldup or to your phone.