With a projector do u always need a screen, or can u use a blank wall. If so, does the wall necessarilly need to be perfectly white. Would different types of paint, or mayby even the material (wallpaper or plaster) make a difference.
You can use a wall, it doesn't even have to be white..... but you will probably get better results with a proper screen. Depending on which projector you use, a matt white or grey screen will give best results.
By different paints I presume you mean matt or silk finish - shiny paint will have a gain effect so the picture will appear brighter.
You could try one of them white, black board things that they use with marker pens for a screen.................don`t know of anybody using them but I thought they were neat with a frame for when not in use
I think that it depends on a few different factors. When I had a LCD PJ with low luminens a magnolia piece of MDF with a pine border gave good results but when I painted it with the now manatory Dulux Ice storm 5 it was too dark, but then using a LCD PJ with over 500 luminens it worked perfectly. I have scene just a painted wall with the ice storm with a black border, and that looked great like a piece of modern art and was quite effective too. Another idea would be to use a roller blind a cream one can be had 6ft from tescos for £20.00. Has anyone tried this avenue and if so was it effective??????