I purchased some Rust-Oleum Painter's Touch Multi-Purpose Flat Black Paint N1976. It is an Indoor Outdoor Easy Clean-Up Latex. The only problem with it is it's not really flat. It has a bit of a sheen when you angle it to the light and will reflect bright projector light. Since I wanted to use this to modify the border on my EluneVision roll-up screen it needed to be flat.
I googled for various paint flattening ideas and ran across one post somewhere asking how much cornstarch to add to the paint to flatten it. Other than that I was on my own. Even prof55 could not help me!!! :rolleyes:
So tonight I tried mixing cornstarch in some warm water. I managed to get 16 tablespoons to dissolve smoothly in 4 oz of warm water. It looked surprisingly like latex paint. Oh I did run across some references to the fact that cornstarch is used in the making of latex paint.
Then I tried mixing 2 tablespoons of the cornstarch slurry in 2 oz of the Flat Black paint. It seemed to lighten the black a bit but not too bad. So I mixed in another 2 tablespoons of the cornstarch just for good measure. I thought it might not be as black but if it was actually flat it would work well as a border paint.
So to recap that 4 tablespoons of cornstarch per oz. of warm water. Then 4 tablespoons of the cornstarch slurry per 2 oz. of Flat Black paint. Assuming I remember it all correctly. It's not really critical at this point. In the end if it worked this was only a starting point.
So did it work? You betcha! I painted a patch with the unmodified Rust-Oleum Flat Black and beside it a patch of the cornstarch modified black paint. They both look black but the untreated paint looks blacker. The cornstarch black has no sheen what so ever.
Now I just need to determine the ideal mix ratio to minimize the cornstarch as much as possible and still have a truly flat black.
Here are some pictures. The background is the shinny side of bristol board (like a screen). The left hand patch of black is the unmodified flat black. The right hand patch is the cornstarch modified flat black.
What can I say. If I can't come up with a better screen paint mix at least I might be able to create a better border paint. :o