What are the various aspects of projection screen material that are evenly compared between brands and how are these fairly evaluated?

The three main criteria of comparison  Color balance/temperature, Brightness and Contrast. The screen’s ability to give neutrally balance is measured by a color temperature meter that seperates the various color intensities which are measured in Kelvins to ensure that a precise color balance or shift is recorded. Brightness is how well the screen reflects a projected image. A light meter is used to measure the intensity of light in 10nm increments. Contrast is the measured ratio between light and dark levels. It is also measured by a light meter or flash meter that can measure both light and dark levels and then calculate a ratio between the two.