Ghost Images on Glass

Create a Post
Val

Val

PFG, Picture Framing God
Joined
Nov 21, 2005
Posts
6,729
Loc
Carson City, Nevada
I'm reframing a Guatamalan temple rubbing on a lightweight fabric. It was poorly framed, glass directly on the fabric, spray adhesive to mount. Fortunately, it came right off the not-sticky-anymore backing with no visible damage. But it had the best example of ghost imaging I've ever seen. Exact intricate detail in reverse, of the rubbng itself on the cheap, regular glass, expecially visible with the glass against black matboard. Almost looks like it was painted on the glass. I'm not sure what medium the rubbing was done with, but appears to be some kind of paint or ink.

I have permission from the customer to keep the glass and will use it as a tool for my "Framing 911" presentations, and at the front counter, as to the imortance of mats and spacers.

A search found this excellent explanation by Rebecca and Hugh
http://www.thegrumble.com/showthread.php?t=15436&highlight=Ghost+Image

... but I would like to find a laymen's way of explaining what causes the ghost images, simple terms that artists/customers can understand. If I tell them it's caused by "salts off-gassing" from the medium, or glass, I know I'll lose them on the spot.

And also an explanation for how the ghost image will adversly affect the art if left on there.

Can anyone think like an artist/customer for a minute and offer a more understandable explanation? Other than "Do this, don't do that, or you'll get this". I had a milder example of a ghost image on glass from a paper mat for the presentation I gave a couple of weeks ago, and it got a pretty dramatic response, but I couldn't explain exactly what it was.
 
How about a vague "the image transfers to the glass without either a double mat or a spacer. If you are interested in the exact chemical process, I would be happy to tell you" answer. Generally customers don't want to know how a clock works; they just need to know the time. But they also want to know that YOU know how a clock works....
 
Those rubbings seem to out gas a lot. I'm afraid even matting won't stop it though I assume it helps. If I had to guess it would be that the paper & or ink is made from plant/vegetable matter that that decomposes, sort of a compost pile under glass. Either that or it's clear evidence that art is actually a living breathing entity contrary to all the things that have been said here in the past & we are killing it by sealing it in a frame & that really is a ghost. Whaduyathink?
 
Terry Hart cpf said:
Those rubbings seem to out gas a lot. I'm afraid even matting won't stop it though I assume it helps. If I had to guess it would be that the paper & or ink is made from plant/vegetable matter that that decomposes, sort of a compost pile under glass. Either that or it's clear evidence that art is actually a living breathing entity contrary to all the things that have been said here in the past & we are killing it by sealing it in a frame & that really is a ghost. Whaduyathink?
Click to expand...

I reframed an Inuit print not too long ago that was previously framed with double non-archival mats. Even with the space provided by the double mats, there was a distinct ghost image of the print on the inside of the glass. I wish I had taken a picture of it as it was quite interesting. I'd have to agree with Terry that sometimes even matting won't stop ghost images from appearing.
 
More Ghost Questions

* If left there, how would the ghost image adversly affect the original art? Or would it, other than the loss of clarity through the glass? This one looked as if the glass had actually been etched.

*And if the chemical in the ghost image would adversly affect it, would leaving it unglazed actually be better for it, letting the gasses go "out into the universe"? I can't bring myself to leave it unglazed, especially in our area, where dust is our largest commodity.

*Will the off-gassing eventually stop, or will it continue as long as there is ink in the fabric? And is the fabric itself contributing to the off-gassing?

These questions are pretty much to satisfy my own curiosity, as I think Ellen has a good point. (My husband, for one, will tell you how a clock is built when all I asked for was the time...drives me crazy!) I spent quite a time searching on this subject and never found any of these answers. But if asked, I would like to be able to answer anyway.
 
Other than contributing a flippant answer, “the image is trying to escape”, Val poses a very interesting question.

If the dye, pigments, inks, etc. are “outgassing”, why do they leave such a distinct impression even if the art is separated from the glass with a spacer or a mat?

It would seem to me that if a frame was hung vertically, the “gasses” would disperse more or less uniformly so that the glass would have a more or less uniform, cloudy haze and not a distinct image on it.
 
Oil based inks, like oil based paint, emit volatile fatty acids and other gaseous compounds as they oxidize (cure). It's normal and expected.

Like most chemical reactions associated with ageing there will be

-an induction period, when nothing much happens
-a reaction period, when most of the activity happens
-a residual period where there is only a small amount of chemical activity going on

So yes, the ghosting will be less likely to happen, or happen only very slowly, the older the piece is.

I have never seen any physical evidence that the ghosting hurts anything but it will, of course, obscure the image a little.

I don't think there is any doubt that it is better to protect the art from the outside world with glazing than to worry about ghosting on the glass, which is easily cleaned or replaced.

You can use ArtCare to help trap volatiles coming out of the reverse of the art. Maybe someone will develop glass with zeolites! : )

Rebecca
 
Gee, Rebecca - since zeolites start out life as kwartz-like crystals perhaps they could be incorporated into glass!!!

I have always been fascinated by ghosting on glass - and my theory about an image appearing rather than generalized cloudiness has something to do with dark and light areas of the image and absorption of light. Does that make any sense???

Somewhere around here I have several attempts at photographing ghost images. They prove to be as difficult to photograph as real ghosts!
 
Mar,

I had been thinking along those lines, too, and, maybe, we are partially correct. But that doesn’t address the whole situation.

It would seem that darker areas in the art, when exposed to light, would become a tiny bit warmer than the paler areas, become more “excited” and emit more “gas”. Hence, the “ghost”.

But, why would those gases in a vertically hung frame travel perpendicular from the surface (in essence, following the direction back towards the beams of light) rather than diffuse and cloud the glass?

I am still puzzled.

Where’s Don Herbert when you really need him?
 
I think it is because the glass is so close to the print - usually only separated by the thickness of a 4-ply window mat, and sometimes even less it the print bows out at all. When glass is further from the print there likely is more diffusion.

If you like conservation physics puzzles and amusing writing, you will LOVE Tim Padfield http://www.padfield.org/tim/cfys/

Rebecca
 
Create a Post
Back
Top