[JeremyJ]

I'm just about to paint my DIY screen. I was thinking (out loud) that maybe if I painted the screen with a silver paint, then covered that with the final grey paint, some of the silver's reflectivity might show through. Hopefully just enough to brighten the whites, while the gray will darken the blacks.


Am I crazy?


Jeremy


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D-ILA, HTPC, HDTV, Panamorph(?)

"It's a higher power telling me through bunnies that we're all gonna die!"--Anya

 

[cottonpickinbird]

Several months ago I painted my own screen. On this forum I found a lengthy "how-to" that Don Stewart had posted here on this subject - maybe you can search and find it. Anyway, I used (as he suggested) the flattest and whitest paint I could find, then put several coats on. (He also suggested sanding between coats, which I did not end up doing). I built a series of curtains all around the "screen" on my wall and it looks great. The picture quality is really great - more than fine until I can one day afford to buy a real (Stewart) screen.


All the posts I ever saw about grey or silver basically ended up saying don't do it - go white.


Good luck!


jwc

 

[Colin]

This post takes the sceinic route to address the question of a silver backing, so please bear with me.


I am not looking to make a grey screen, but just the opposite - a very white one. I have looked at some art stores and have come up with an acrylic binder - essentially the sticky stuff that makes paint... well paint. It is a very watery (actually about the viscosity of alcohol) into which an artist puts the dry pigment of their choice. In addition to this I have ordered and now have in my grubby little hands 4 lbs of Magnesium Carbonate which I ordered over the internet for about $7.00 a pound - (way more than I needed but a $25 minimum order)to use as pigment. The artist's handbook which is a pretty technical manual of chemistry related to artists uses states that this is one of the whitest pigments known to man and it binds very well with an acrylic medium.


So I am planning to make my own paint, and with the addition of some pearlescent powder (also available from an artist's store) I should be able to achieve a non-shiny extremely white surface with a pearlescent finish. Also, by using a lot of the liquid to make a watery paint I hope that it will flow well and thanks to gravity will leave a wonderfully flat surface. I am also thinking about adding some silver pigment to the white directly or in another layer behind the final front (top) surface of paint.


In the past I have experimented with spraypaint (bad idea in terms of final finish) using a white layer on top of a silver layer. My theory is that the light passes through the white layer pretty easily and is mostly reflected by the silver but then is diffused by the white so that it doesn't look to 'hot' and doesn't causing hotspotting. I don't know how much silver would help behind a grey coat because not too much light will ever really hit the silver, but for white screens it may be just the ticket. Its still worth a try. Does anyone have any experience with this. In the end if this causes a probolem I can just put a couple more layers of the white and never have to deal with the silver. Make any sense? When I start doing this I'll post my progress.


For you grey liking people try some carbon black in with a mix like mine or even some gesso which is essentially the same mixture as mine which substitutes Calcium Carbonate with my Magnesium Carbonate and maybe throw in some pearlescent powder. You can really experiment with abandon because if you don't like the surface you can always paint over it and all you get is a more durable screen.

Colin

 

[cutman0122]

Jeremy,

I've had the same idea, I've got a different appraoch though. I don't have the time, or access to any of these materials, and I don't even know if any of this stuff can be had. So I'll go ahead and share it, maybe somebody else can run with it.

Take a high gain screen, instead of coating with paint, apply gray highlighting fluid over the entire screen! This would be the ideal way I think, since it allows light to pass through and gives us the proper shade of gray at the same time. I believe this combo would give you a high gain gray screen. BTW, is ther such a thing as a high gain gray screen? Some of the problems with this idea of course are:

1. Where to get gray highlighting fluid/liquid! Never seen it, but I don't see why it can't be made!

2. Where to get that much highlighting fluid/liquid!

Maybe 1 & 2 can be special ordered.

3. How to apply it in uniform across the entire screen. As we all know, it's easy to see where highlight marks overlap on paper.

Well that's my crazy idea, what do you guys think?


Gerald

 

[cutman0122]

Just another thing to add to my crazy idea, instead of highlighter fluid/liquid, how about dye? I think some of that stuff the kids use for easter eggs are translucent just as highlighters. Again, don't know if it can be had in gray, but maybe a mix and match of different colors can produce the proper shade. Cheers!


Gerald

 

[JeremyJ]

Here is what I tried as an experiment. I bought a grey paint (glidden "Veil" from Home Depo) and I bought a bottle of Behr "Pearlescent" in White Opal color. This is an accent paint designed for accent effects.


On a sample of my material (painter's canvas), I painted the top with the "pearlescent" material then painted grey over it. On the bottom I painted it grey and then painted over that with the pearlescent. In the middle I painted just grey.


The black levels were improved significantly on both. The grey over pearl looked exactly like the grey only section. So I guess the grey paint is opaque enough to cover the pearl.


However the interesting area was the pearl over grey. The black levels weren't quite as black, but the whites were vibrant! Actually too vibrant, in fact it looked like an ultra high gain screen.


Sadly, two problems make it an unusable option. Severe hotspotting and very uneven application. But conceptually it worked really well.


Then I said, what the heck (yes we say heck in Utah), maybe if I mix the pearl in with the grey it will smooth out the uneven application problem. Sadly, when I mixed them all together and painted my entire screen, the "Pearlescent" was totally overwhelmed by the grey and was lost.


I could see this technique working if, the Pearlescent could be applied as an aftercoat, and only if it could be applied evenly.


Any suggestions?


Jeremy


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D-ILA, HTPC, HDTV, Panamorph(?)

"She saved the world...

a lot." -- Buffy's Epitaph


[This message has been edited by JeremyNeish (edited 06-10-2001).]

 

[kelliot]

If you take a look at some of KBK's paint threads from last year, the pearlescent over grey was something he was looking at and had some interesting results.


Painters canvas has too musch starting texture and probably needs several coats of a smoother. I personally don't think that the color of the smoothing layer matters much.


The gray layer should be matched to your projector but the best results have a reflectance of .6-.8 for most common projectors.


The pearlescent coat is subject to hot spotting if not done right. KBK is the expert on this subject, but my recollection was that he mixed it down until the hotspotting disappeared. It should be an aftercoat.


For uniformity, a good finishing sprayer is probaby needed for all coats and multiple coats need to be applied.




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Ken Elliott

 

[KBK]

Yep. The proper mix of pearlecent over grey will give you what is effectively.. very much like a well known grey screen out there. Not anywhere near as exact.. in many important ways, but at least you will have the satisfaction of having created something yourself. Color balance will be your main enemy. Experiment till the cows come home.


The max number of screens I have had around the house as experimental bits topped out at 21 samples... if I recall correctly.


I thought I was really good, untill the paint engineer from the company i am involved with took over.


Remember the scene in "Close Encounters of the Third Kind", where the keyboardist is trying to communicate with the UFO on the runway? And suddenly.. the man in the tower says," we're taking over this conversation...Now" And he flips the switch. Suddenly the Keyboardist's best efforts look like a joke. Well, the engineer took over... And I looked like a mudpuppy. ('Muddy.. the mudskipper..'--Ren Hoeck) So, maybe soon.. but I have been saying that for a while. I have deliberately kept quiet on the forum, here. No product, so I keep quiet.


So, We will be using the worlds best acrylic paint systems..(and that is by a wide margin the best available).


Le me give you an example. I have a 1.5 gain screen here, done with the CRT 1.6 paint. I put it on a high gain cheap matte finished piece of crummy vynil. The back side of the vynil is really hot and glossy. I rolled the screen up and put it aside (this is 6 months after I initially painted it) I went to unroll it after it had been sitting for 3 weeks. The paint had begun to stick to the backside of the screen, and the paint surface had flattened, and become glossy. Unrolling it required force (pounds of it), and stretched the vynil, in a very inconsitent fashion. I thought it was ruined. But, I hung it anyway. After 1 day, all of the surface texture had had 'bounced back' to it's original shape. No faults. And, the surface is washable. So, we will be issuing product, but it must be perfect, of course. So, we wait. Is it done yet? Is it done yet? I'm tired of waiting too. Oh yes. 50 year life span on this paint as well.


For more info, search for the 'custom screen paint' thread.


------------------

goosystems.com


Ken Hotte

[email protected]


[This message has been edited by KBK (edited 06-11-2001).]

 

[Colin]

Hello all-


Gerald - what is highlighting fluid?


Ken Elliot - when you talk about a smoother is this a specific product or just a number of coats of whatever you are using.


Also, people have talked about the problems with mixing a pearlescent paint with the main paint. Are these pearlescent paints in a liquid form or are they powdered pigments. If they are liquid would a powdered pearlescent 'go farther' thus negating the need for another layer and thus a second opportunity to screw it all up.

Colin

 

[kelliot]

When I talk about a smoother, it is descriptive, multiple coats of paint smooth canvas.


The vinyl KBK talks about is naturally smooth and textureless.


A textured screen is like adding screen door onto a perfectly good projector.


As for pearlescent, I've mixed paints but never overcoated. My experience comes from failure. I have had big problems with high gain mixed paints revealing texture.




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Ken Elliott


[This message has been edited by kelliot (edited 06-11-2001).]

 

[cutman0122]

Colin,

I don't know the exact technical term, didn't even bother to look up what's in it. The highlighter fluid/liquid I'm referring to is the contents of the marker called highlighters (used for highlighting text or certain passages on just about anything on paper). The office supply AKA Highlight markers, or highlighter pens. Hope this helps, sorry to confuse! Cheers!


Gerald

 

[cutman0122]

I have gone and done it! Experimented with the Da-Lite HP sample they sent me, and it works as I theorized...well sort of!


Tried the highlighter pen (pink, it was all I had), and just as I thought, the HP retained it's high gain, retro-reflective properties but now with a different shade!


Next I tried was dye. All I could get was black, but it turned out it was all that I needed. Mixed it with water, and applied to the HP and got a shade of gray. Again, the HP retained all it's properties, so much so that the gray half of the sample I made was not showing up at all when viewed as close as you can get from the PJ. Re-applied more dye, this time without any water mixed in (concentrated black dye). Left it on for about five minutes (the longer you leave it on, the darker it gets), and rinsed away the excess with water. Got a dark shade of gray this time, and still the HP retained all it's properties, and got more of the gray screen effect I was looking for(it was the same shade but slightly darker than the Da-Lite super wonderlite). Still, as dark as it was, the effect was minimal, again when viewed from about where the projector is located. It's just a matter of how dark you can get gray on the HP at this point, but now for the downside!


When veiwed off axis, especially outside the width of my screen, retro-reflectivity rears it's ugly head even more, for me anyway! The further you move away from the optimal viewing angle of the HP, the darker the shade of gray becomes. In effect, this exaggerates the downside of retro-reflective screens. Now, instead of the HP reverting to say a 1.0 gain screen when veiwed off axis, it becomes gray directly proportional to the veiwing angle.


Before I even thought about this experiment, the HP's retro-reflective properties after seeing it for myself, is what's really turned me off to it. Applying dye to get a gray HP has made it worse. But on a good note, this experiment proves it works. The next logical thing to do is to try it on the other type of high reflective screens out there. The non retro-reflective type like the one Draper makes, or is it Stewart? Anybody else care to try?


Gerald