I guess it depends on what you think looks good and what you are trying to do with the projection.
If you noted, some of the
Rosco screen materials and most of the
screen materials from projection
screen companies like Stewart Filmscreen, Hurley Screens, Da-Lite,
Draper,
etc. will have values for viewing angles and
gain. The two are often interrelated and also relate to both the viewing area and the
projector brightness required. High
gain screens typically have narrower viewing angles, they focus the light hitting the
screen into a more defined area.
Screen materials with a wide viewing angle are typically lower
gain as they diffuse the light over a broader area.
What many people do not realize is how much this can affect the
image brightness and thus the
projector required. Using the
Rosco screen surfaces as an example, the Black and Twin White can both be used for rear
screen projection.
Gain on the Milky White is a peak of about 0.35 while the peak
gain for Black is about 2.3. That means that with the same
projector the Black
screen would produce an
image over 6-1/2 times as bright as the Milky White
screen would, but it would be viewable over a smaller area. That could mean the difference between needing a 2,000
lumen projector or a 12,000+
lumen projector for the same
image brightness. On the other
hand, when dealing with multiple images and.or wide audience areas, narrow viewing angles can be problematic and you can end up with a very small area that has good viewing for all of the images.
Another factor is ambient light. When ambient light hits the
screen during projection a black or grey
screen can make the
image appear brighter by minimizing the
effect on the black
level and thus the better maintaining a higher contrast ratio. Darker screens also tend to not be as readily apparent when ambient light hits them while nothing is projected.
As ruinexplorer noted, you typically want to avoid wide angle lenses with high
gain screens or very long
throw lenses with very wide viewing angle screens. For example, with a wide angle
lens the light at the edges of the
screen is hitting the
screen at a much shallower angle of incidence while the high
gain screen is then trying to focus all the light back into a narrower 'beam' off the
screen, the result is numerous
image aberrations,
drop off at the edges and so forth.
So it usually comes down to balancing all of these factors along with the 'look' you feel works when there is no
image projected. If you go with a material not specifically made for projection then a number of these factors are typically going to be unknown, which is why it is so difficult to say what might work in those cases other than simply by trying it.