Originally Posted by skipford
I would go white over white (I think your Epson is going to give the blackness even with higher gain).
Besides the fact that the Poster referenced to has already stated his intentions, I must disagree....even though I have installed many 8350s (26+) and was among the first to do so.
The brightness of the 8350 will work against the stated contrast specs on a purely white surface. It's 50K:1 rating is based upon the use of a optimally calibrated Cinema Mode, with the Auto Lens Aperture feature engaged and the lamp output set on Low Lamp. That means if the Normal Lamp Mode is used on a white surface, contrast will take a hit. And with a Spandex Screen, Normal Lamp Mode is almost always employed.
Conversely, if one has the Lumen output at hand, and the screen size / gain specs do not work against them, then the use of a Gray surface can result insignificantly improved black levels. And in this instance, since the Gray that is imparted, and the resulting attenuation comes not from the the Screen's 1st surface level but from the underlying material, the topmost white surface is allowed to retain and return a higher degree of white and color dynamics than a Gray would otherwise.
With advanced Gray painted surfaces, the same is accomplished using reflectivity enhanced mixtures. With Spandex, it's all about what the forward surface does, and how the rear surface both stops a greater amount of light from getting lost out the rear, while also deepening the shades of any light that is being reflected back through the top layer.
This is borne out additionally by the fact that some actually advocate using Black Spandex as a rear layer, which in turn both further attenuates light (ie: loss of more gain...) and deepens Black levels all the more. And they swear by the end results they get. I personally do not feel the additional loss of gain is worth the gains in Black Levels, but the again, if one was using a 3000 Lumen PJ with 10K:1 contrast, that would alter my thinking accordinly.
Sooooo.....any PJ that has adequate lumen output and yet "only" sports a contrast spec of 50K:1 can be better served by using a high contrast surface. And any multi-layer surface that provides an initial white layer will do all the more effective contrast enhancement without the Whites taking a significant hit.
In some respects, that means some degree of actual increase in "off the screen" contrast is happening....the Holy Grail of any such screen, and the basis of many claims made by Mfg Screens. Albeit few are valid.
I believe I would buy 6 yards total (3 for each layer) just to be sure. You might get away with 2 yards per layer but I wouldn't risk it. As far as throw distances and fl, I have no idea. I would try a white bedsheet in the meantime and see what you think.
3 yards ea. is correct, and hopefully they were ordered to come rolled....not folded. Some have had issues with stretching out wrinkles.