Welcome to AVS's Diy Screen Forum!
Hmmmmmm.....a hard man.
Well, with the 720, and because you don't want to even try painting....the best, least expensive "Hang-N-Shoot" material for you would be Do-able Board. Usually a Lowes offering. Or....Lowes or HD might have a similar product. It cannot be glossy in the least.
But sadly Bro....both of those items as well as Black Out cloth are white, and so being...you can kiss any real ability to watch programing in ambient light goodby.
You pick up a sheet of Doable or similar "NON-Glossy" White board.
Have the location you get it from cut it to 82" x 48". (...we are shooting for a 90" screen here...)
Buy 2 Tubes of Liquid Nails
Buy 4 sticks of 3.25" Primed MDF Baseboard Trim
Buy 1 Quart of Behr Flat Interior Enamel tinted with Disney's Mouse Ears Black
Buy 1 Good 3" Brush
Now comes the nasty.....
If you even were to consider trying to build a frame for a BOC screen, between the time and expense you'd be spending more of each instead of simply picking up a Couple roller, a Can Of Behr Flat Interior Enamel in a neutral Gray, and simply rolling on two nice even coats. No contest really. And when you stop to think that if you do so, ambient light performance will improve 150%....where's the argument? (...you can always spray your next effort...because there will be a next effort....
But that Murphy guy...I heard he has a home up in Ventura, and likes to trouble LA'ers at times? Well supposin' you can't find any Doable. Home Depot and Lowes also carry something called Thrifty White Hardboard...a piece of material that costs all of a whole $13.00. I know HD will cut it for you...and if you simply take care rolling onto that material, you should spend all of 1 longish day getting the Screen done and up.
The size I mentioned above relates to these instructions.
The Board can be rolled while Flat on the wall, held up by 6-8 screws shot through the 2" of extra Boarder that is all around the 78" x 44" actual Screen area. Cover 1-1/2" of the two inch Boarder area (from the outside edge in) with Painter's Blue Tape, and then paint all the way out as close to the edge of the Tape as possible.
While the screen is Drying with each of what should be 2 light coats and one final normal coat of the Gray, cut your 4 pieces of trim so the inside edges of the corner Miter Cuts are 78" x 2 and 44" x 2
Paint the Trim using a Brush and with care to avoid obvious Brush marks. Detail out the side edges, but do not paint the rear.
Take the Dried, finish screen down and lay it Flat on a hard surface. Apply the Liquid Nails to the painted Screen board as a long ribbon 1" in from the outside edge. Not too thick....but at least as thick as a big School Pencil in diameter. Place the Trim onto the Board, press it into place with FIRM pressure (...wear some clean Cotton Jersey Gloves to avoid marring the nice Black finish...)
Now go away....let the trim set up and dry HARD overnight. Now all you have to do is get a Hangman French Cleat, attach one piece to the rear of the Screen with Glue & Screws...the other to the wall, hang and enjoy the exclamations of your fellow cohorts.
Oh yeah....hang the projector at or as close to 9' 3" as you possibly can. You want maximum Lumens to get maximum fl on the screen.
Once again....ya gotta go Light Gray in the least, so the above is the quickest, easiest, and least expensive way to make a very portable (one man easy carry) and very acceptable Screen.