Image transfer to glass

Create a Post
S

Stray Feathers

CGF, Certified Grumble Framer
Joined
Jul 1, 2010
Posts
104
Loc
Ladysmith, BC
I've seen examples of images that have transferred to glass (a ghost image) when framed against the glass with no mat or spacer. Today I opened up an older John Seerey-Lester print, double matted, and there is a clear ghost image on the glass. How does this happen without the art contacting the glass? I thought initially it may have been because there was too much packing behind the centre of the print (pushing it against the glass), but it seems to be across the entire image.
 
I am sure someone here can give all the chemical reasons for this, but as I understand it, it is just humidity and heat. Light hits the glass and creates heat. Moisture and off gassing inside the framing package condense on the glass. Different colors in the image will cause different temperatures and therefore different amounts of condensation. Remember that the moisture in the air is not JUST H2O. There are minute minerals as well as other impurities that are contained in the condensation.

I hope this helps.
 
So, as a relative newcomer, if off-gassing from prints is an issue, are we fighting a losing battle to frame machine prints for the long-term? Is there a best-practice to minimize the problem? Might it have something to do with the non-acid-free cores in the old mats?

And thanks for the prompt replies and good information . . .
 
Solvents in the inks evaporate over time as the ink cures. Framing certain prints before this has occurred will leave a ghost image but it is no big deal just the natural process. Clean the glass an pop it back together and it shouldn't happen again.
 
Off gassing is only one problem. The other is still the heat and humidity. Some images will get ghost images no matter what you do, and others won't.
 
ghosts on glass

As with all ghostly issues, one can never be too sure, but the white deposits on old glass have tested out as sodium chloride, salt, in the past. Sodium can come from glass and chlorine from various sources as the glass is expose to wetting and drying as the sunlight falls on it when it is cool and condensation occurs on the glass and drying, later. The pattern may come from the fact that strong light will dry the dark areas, before the light ones, causing moisture to move from one area to the other and the salt deposition with it.


Hugh
 
Oh great Hugh,

So now, not only do we have to squeegee down the shower,
but the inside of the frame glass too? :D

I knew it was a "salt deposit", I just didn't understand why
the dark areas didn't get as much.....

Wow, now if I could just turn that info into a 2 hour class.....
Thanks again for bringing us the best information from
the state-of-the-arts and science institute.

We'll miss you when you retire in what..... about 47 more years? :D
 
Baer Charlton said:
I knew it was a "salt deposit", I just didn't understand why
the dark areas didn't get as much.....

Wow, now if I could just turn that info into a 2 hour class.....
Thanks again for bringing us the best information from
the state-of-the-arts and science institute.
Click to expand...

I'm betting it will mentioned in "Conservation Chemistry" in Las Vegas....
 
preservator said:
The pattern may come from the fact that strong light will dry the dark areas, before the light ones, causing moisture to move from one area to the other and the salt deposition with it.
Click to expand...

That sounds like what I found in this case - the ghosting looked mostly whitish, as opposed to some I've seen where colour appears to have transferred to the glass. In this case there was a clear, sharp duplicate image of parts of the print (in this case Bald Eagles). Are you saying this could happen in the process you described? Amazing if true . . . And can you comment on whether there would be any difference in the effect with two or one or no mats (i.e with the artwork touching the glass)?
 
Condensation does not really care how many mats the art has, it cares about moisture and heat. Think about where things are hung in a house... how many things are hung on the wall outside the bathroom? The wall has the moisture from the bathroom, and because of Osmosis, the moisture will go from an area of high moisture (the bathroom) to low moisture (the hallway) and end up in the picture. Impurities in the air, including salts and other airborn minerals, will be left behind on the glazing after the moisture evaperates.

Plexiglass does not do this as often, as it tends not to react to the temperature the same as glass.

As Hugh pointed out, it is the reaction between the temperature and the moisture.

I would guess that having more mats, therefore spacing the glazing farther away from the art, would allow for the air in the package to adjust to changes in temperature without causing condensation. (But I have not tested my theory.)
 
Condensation will form inside the frame's glazing any time that surface becomes a certain degree cooler than the air inside the frame, when humidity is present. For example, at 50% RH and 70 degrees F, condensation would form on a surface when its temperture descends to 50 degrees F. Moisture would continue to condense only until the temperature differential diminishes, which usually happens quickly, as the material adapts to its surrounding air.

The exact conditions vary with temperature an humidity, as shown in a Dew Point chart. Here is a previous thread tha discusses condensation issues.
 
Create a Post
Back
Top