As an afterthought, I found it repugnant to suggest that such a huge application must be considered "acceptable" even if it had sparklies, hot spotting, or anything else considered detrimental, and made acceptable on the weight of it's being BIG.
Now I'm all for "Big", as most know, but "Big Ugly" isn't on that list.
Of a certain, the surface needs to start out being very Reflective White as a "Base", but by evenly dulling that just a bit with a flexible dusting of a Matte Glaze there should be results that are decidedly better than "make do". Control and use that reflectivity. It's done just about everyday somewhere using Glossy White Hardboard (Thrifty White) and translucent Gray paint, so doing so with a lightly applied Clear Matte dusting should maximize the potential of a White Tarp.
The real quality will come in the presentation/installation of such a large Screen. If it can be taunt, flat, and unwrinkled, it's gonna be all that it can be.
And at 288" x 162"........that's a LOT!
But it seems to me that at the sizes just discussed, reflectivity isn't so bad if it's evenly applied.
Really...it's the PJ that matters. I noted recently that a Online Vendor has a Epson, 2000 lumen Projector - DVD Combo w/Speakers for a sub- $600.00 hit.
Using the Panny AX200u as a guide post, a 288" x 62' surface would have to be of a minimum 2.0 gain just so that the foot lambert off such a screen would be about 6 fl @ 33' throw.
Trying to put a curve on 288" outside is out.....,
Trying one's best to tie / stretch out such a large Tarp and doing that successfully would be enough an accomplishment. Best that such be the first order of importance.
Afterward...and while stretched, one should consider dusting on something like S-I-L-V-E-R over about 5 coats would ramp up such a Tarp into real "OMG" status. S-I-L-V-E-R is flexible enough that if one procured a empty Cardboard Carpet Tube, such a fine example of Overkill could be effectively rolled up & stored and kept in excellent shape for many future viewings.
Yeah, by doing it that way...sure it would be a logistical PITA to store for many, but hey...if you think BIG, why stifle or degrade the effort by introducing wrinkles and folds ?
Yessir, "Quality" is all in just how much one is or is not willing to do the minimum required to obtain the maximum results. For so many....the "minimum" is often far removed...and lagging behind what is / should be done.
Buy a Tarp ...........................$60.00
Buy a Wagner CS....................$60.00
Buy S-I-L-V-E-R components...$30.00
Total spent making a 330" diagonal Screen..$150.00 *
And Guys, just scale back to Screen size to something under "Big Top" size and it all just becomes easier. Dem Dudes on the Outdoor Screen Forum....now there are some Fellows who want it all. *
Ok...ok. So you also gotta buy some Hardware, Bungees, Cushions and Beer. Waddya ya Want fer 'Nuthin?