Screen reflection readings go hand in hand with spectroradiometer readings in that you can actually have a bad spectro reading and yet still achieve good results with a reflection reading. Take a look at the Supernova readings for example. The spectro reading looked terrrible and yet the result of the reflected reading was worthy of the ISF certification for the dnp Supernova. The reflected readings are measurements of the real performance of a screen material. By the way, I say 'materials' which encompasses all materials. Be it a commercial product or a DIY Product.
The information contained within is a collaboration between myself, wbassett, harpmaker, and custard.