canvass - what my eyes see

Is the canvas raw or was it pre-primed?

Bud is more familiar with artist's canvas and the paints they use on them. It may be one of these Liquitex gesso products or similar.

I think the more important point is that the BOC may actually be allowing some light to pass through. It may not actually be really white either.

If you were wanting a whiter screen you could paint the BOC. You could use Kilz2, Kilz2 Premium , or the Behr ULTRA UPW.

I've lost track of where you are at. Didn't you try the Designer White laminate, and now BOC. I know at one point you were considering a gray screen.

Are looking for a whiter screen now?

So are you wanting a very white screen or were you wondering about using a light gray with some gain?

Most pre-framed canvas panels come with a gesso coating already on and they have a fairly high reflective index. Canvas also comes bleached and raw. The raw is the more yellow looking stuff.

Tiddler posted above that some light may be passing thru the BOC and that is most likely true, but not totally true. BOC is made not to reflect light even though it does that fairly well. But it is intended to stop light. there is a inner black layer and if some light makes it thru the white it should be absorbed into the black. So you can be loosing light even though you don’t see it coming out the back side.

Paint is better because for the most part it forces reflection at the surface but it has also been shown some light makes its way into the paint. this property is what allows all the “light fusion” type paints with metallic in the mixes to do their thing and along with mirrors under the paint. Todd has a great thread illustrating this.

Painted canvas works as a screen surface no different than any other painted surface except that it has a weave texture. It has been widely debated if super smooth or texture is desired and the jury is still out on that one. I have always felt texture played a key part in a lot of commercial screens and in my testing I felt it gave a desired diffusion of the SDE. Others have disagreed.

If I have some time I’ll look closer at the screen shot above and see if there are any clues as to what is working better in that photo. Its very clear the canvas is brighter.