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Titanium dioxide is the most common white pigment in paint, sunscreen, and even food products. It’s cheap, safe, and almost unsurpassed in whiteness. It’s also the baseline for calculating an optical property called screen gain, which is the amount of light reflected from a projection surface divided by the amount of light reflected from a titanium dioxide reference surface. Since titanium dioxide is the pigment used in most white paint, a smooth wall painted flat white has a screen gain very close to 1.

But you can do better. This method applies a high-gain optical projection surface using common, cheap materials — flat white latex paint and glass sandblasting beads. I started out trying to directly mix them (which doesn’t work) and happened on this “sprinkling” method by accident. It gives a much brighter screen surface than paint alone.

Preview

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Steps

Step #1: Determine your screen size.

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Set up the projector as you will use it. Turn it on. Measure the height and width of the image. Plan the size of your screen accordingly. In my case, a single 4'×8' panel made a convenient size.

Step #2: Build the screen

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  • Cut 1×2 frame members with a miter box and saw. Here’s the cut list for my 4'×8' screen.
    • 2 sides 96" long on outside edge, mitered ends
    • 2 sides 48" long on outside edge, mitered ends
    • 2 braces 45" long, square ends
  • Tack the 1×2s in place on the hardboard with hot glue, then secure with ¾" wood screws every 10" or so. Install the screws from the front side of the unfinished screen, countersink them, and fill the depressions with wood putty.

Step #3: Lay out the drop cloth.

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A plastic painter’s dropcloth will protect your floor, but it’s also useful for collecting loose glass beads after you apply the screen surface, so use a fresh one with-out holes. Spread it in a clean area with a smooth floor, and tape the edges down. Set your screen down in the middle.

Step #4: Apply the basecoat.

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First paint the edges of your screen with a brush, then apply a smooth, even coat of paint to the surface with a roller. It’s easiest to just pour the paint directly from the can onto the screen — Jackson Pollock-style — then smooth it with the roller. Let the basecoat dry 24 hours.

Step #5: Ready glass beads.

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Pour out your supply of beads into the tub. A cheap plastic dustpan makes a convenient applicator for sprinkling. With a bit of practice, it’s easy to get an even sheet of falling beads.

Step #6: Apply topcoat.

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After 24 hours, paint the screen edges again, then pour about ½qt of paint onto the screen, distributing it more-or-less evenly. Roller the paint smooth. You want a quick, even, heavy coat.

Step #7: Sprinkle the glass beads.

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While the topcoat is still wet, sprinkle beads generously over the entire surface. You'll recover any excess later, so go ahead and apply them all, being careful not to miss any spots. Once the paint is dry, the surface is hard to touch up.

Step #8: Brush off and recover excess beads.

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  • Remove the excess beads using a soft brush.
  • Give the screen back a few thumps to dislodge any remaining loose beads, then stand it upright for a final brushing. Peel off any flash around the edges with your fingers.
  • Gather up the tarp from the edges into a “sack,” and lift it into your tub. Release one edge and slowly work the tarp out from underneath the mass of beads. I recovered 16 of the 25lbs of beads I applied.

Step #9: Install wall hardware.

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I put in a row of 4 self-drilling wall anchors behind the top edge of the screen, and drove in their screws, leaving about 1/2" sticking out from each. Then I just hung my screen on the screw heads. It’s easy to adjust horizontally, but not as secure as I’d like. A French cleat would probably be the best solution.

Step #10: Hang the screen.

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Put on clean gloves before handling the finished screen to avoid getting oil on it. Lift it into position and hang it in place.

Step #11: Use it!

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Turn on your projector and refocus and adjust the image as necessary.

Conclusion

The final surface — glass beads embedded in latex house paint — is surprisingly tough. I was concerned that flexing the screen would cause the beads to flake off, but the latex paint is still flexible after 2 years. I almost think you could apply it to a thin surface that actually rolls up.

Another pleasant surprise was that, at viewing distances, the surface treatment is remarkably tolerant of small imperfections, and does not require a very smooth texture. I believe it could even be applied directly to a textured wall, thus eliminating the need for a separate screen altogether.

This project first appeared in MAKE Volume 35, page 98.

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.


Comments

  1. Goli Mohammadi says:

    Cool ideas, Mike! Please share if you work through any of these applications.

  2. Sean Michael Ragan says:

    Not necessary, IMO. This stuff is 80 grit, making it 190 micrometers in diameter on average. Silicosis is not a risk until the particles get down to 10 micrometers or less, so that’s a pretty comfortable margin. Particles also need to be crystalline (and of particular crystal structures) to cause silicosis, and glass beads are not crystalline, but amorphous. They’re also not pure SiO2. But of course anyone who is concerned about it should not take my word for it, and should err on the side of caution, and should wear a respirator.

  3. Sean Michael Ragan says:

    Thank you! Yes, the whole scheme I’ve used to hang the thing from the wall is really pretty crappy. It has worked, so far, for me, but I would not officially recommend it to anyone. A french cleat, per Scott Baker’s comment, above, seems like the best and most elegant way to do it. When/if I do it again, I’d use a french cleat.

  4. Sean Michael Ragan says:

    Hi Lance,

    Actually my projector is mounted on a 2′ piece of MDF shelving from the hardware store. I’ve drilled holes in the shelf and put bolts and washers through that secure the projector to the shelf using its built-in threaded mounting holes.

    The shelf, in turn, is mounted to the wall using “Cable Shelf Brackets” from The Container Store:

    http://www.containerstore.com/shop/shelvingSale/wallMountedShelving/brackets?productId=10001032

    The nice thing about these brackets, for this purpose, is that the shelf doesn’t have to be mounted at 90 degrees to the wall. You can stand under it and lift it up, eliminating tension on the cables, and then adjust the four corners up and down as you want to adjust the image, then let the shelf go, and gravity will hold it in place. So it’s easy to adjust.

  5. Sean Michael Ragan says:

    Jay-

    Thanks so much for your comment, for your enthusiasm, and for your reported results and advice to others. Glad you’re pleased, thanks for reading and doing and sharing.

    Cheers-
    SMR

  6. Sean Michael Ragan says:

    I dunno about cloth, but my first experiments were on cardboard, and I
    observed when I discarded them that the top layer of the cardboard
    bearing the mixture of paint and sprinkled on beads could be peeled
    off (indeed, it tended to come off as a continuous sheet) and rolled
    up without significant flaking of the paint and/or beads. Granted,
    the paint was relatively fresh at that time, but latex stays flexible
    for awhile. I keep meaning to experiment with this, actually, but
    haven’t had the time yet.

  7. Chuck says:

    I made the PVC outdoor movie screen from the Geek Dad books, and I am using a 5′x9′ sign banner as the screen. It works great because it is simple to roll up and store. My guess is that rolling up something like this will either lead to permanent wrinkling or cracking.

  8. Ethan Terra says:

    I know this is an older thread but none the less I found it very helpful in restoring my old screen to better then new luster using this method.

    Now I have built a lot of DIY screens over the years for events ect and you must keep in mind that your picture is only as good as the surface it’s projected on.

    Assuming that your willing to go this far for a home theater take a few extra hours and a few extra dollars and go the distance.

    The best screens are bound to a frame.

    The frame can be made out of metal or wood your choice. I suggest using metal because of its overall durability.

    The skeleton is made just like a “picture frame” with angles that fit together to form each corner and a horizontal and vertical cross bar(s) in the center for support. That frame becomes the skeleton.

    Depending on the thickness and width you will then measure out (half inch/quarter inch FROM THE EDGE) and screw in the “””MALE SIDE””” of metal button snaps every 2 inches all the way around the exterior edge of the frame. (((NOT THE CENTER CROSS BARS)))

    The screen material will need a LEATHER RUNNER double stitched onto the edge of the screen material. You will need to do a couple of test fittings to get the measurements right.

    After the runner is in place you will install the “””FEMALE SIDE””” of the metal button snaps to the exact measurement as the snaps on the frame. Again do several test fittings because these metal snaps will pull the screen TIGHT around the frame.

    After the snaps are installed into the leather runner block out and paint the screen.

    After your done with the desired number of coats install the screen one side at a time. By the last side you will find yourself stretching and pulling with both hands to get the snaps to attach, YOU WILL KNOW YOU DID IT RIGHT WHEN YOUR ANGRY & YOUR THUMBS HURT :D

    After the screen is attached you should find that the entire screen and skeleton weigh about 25 pounds give or take.

    I have found that the 8 to 10 inch plant hangers at Walmart are the easiest way to hang the screen from the wall because they have a “SUPPORTED” hook end that the frame can be hung from. I use two of them, one on each side screwed into the stud and I have never ever had a problem with them bending/twisting ect.

    If you have any questions or want pictures I would be happy to provide them.

    My Best.

    Ethan

    1. terre says:

      Where are all these makers?? The ones that do more than have meeting and talk about what they want to EvENTUALLY do? I am eager to support and learn from makers but around my area, they seem to want to step into a ready to work space, already outfitted with pristine walls, tables, shelves, and mostly- cool tools!

      1. What you have indirectly described is a hobbyist. Hobbyists like kits to put together for fun in their spare time and club meetings where they can socialize. There’s nothing wrong with that; they are a distinct subgroup of Maker that help make websites like these possible. The more gung-ho put-it-together-from-scraps-because-I-can type of maker is more likely to be the one to design the kit. And of course, hobbyist types may become the gung-ho types if need motivates them. The ecosystem of the Maker world is a diversity of types. Some make their own tools. They’re likely to spend more of their time making and less of it commenting online or at meet-ups. There is definitely a distinction between someone who will make their own soldering iron because they need one and someone who orders one and talks about their upcoming project with anyone who will listen while waiting for it to come in the mail, but in the end, both melt the solder into something they make.

  9. the nerdling says:

    what are the pros and cons of this compared to a commercial projector screen?

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