That youtube video is impressive.
I guess after a year of watching movies on my JVC, I'm beginning to notice more of the abberations in my cinema. A bit like living in a house for years and one day noticing that smudge on the ceiling. It's always been there, you simply never noticed it until now.
I tried the 1.0 gain screen material on my grey screen and in the dark (PJ off), no difference. With the PJ on, pic hidden, the white material stood out a bit, but not in a big way. With the in-built green calibration grid on, there was no difference at all. The blacks in between the green lines was just as black on the white material as the grey. With colour patterns, the blacks were washed out on the white, but that just demonstrates that it's my room that needs some more treatment (suede \\ velvet) as the colour patterns did light up the room, but the green grid didn't (black paint isn't all that black under light).
The 1.0 gain material from Harkness was impressive for colours. Way more image 'pop' (put the grey screen to shame on that level), but the blacks suffered during light scenes (compared to the grey screen). Now I understand why people want a dark room to keep the blacks in check.
Based on the above, I'm going to add more black material to the ceiling and walls, and perhaps the rear of the room, and try some bias lighting behind a 1.0 gain screen.
A bit off topic, here is a picture I've taken with some black materials. I wanted to test them before ordering a big roll.
The projector stand is painted in 'Dulux trade, flat matt black' (their darkest black). High power flash to highlight which is best....the winner.....Devore. At half the price, EPRA's Tripple black comes a very close second, but the picture does it a dis-service. It looks a lot darker than in the picture when you're not blasting it with light. In fact, under normal diffused light, it's difficult to tell the difference between the two. The tripple is not as acousticly transparent as the devore though. It got a backing on it that reduces air flow, and reduces stretch. The Jersey is more acoustically transparent than the Devore, and it's stretchy too, so a good contender for a speaker covering.