Ever have a drymount pop due to temp, humidity, etc.?

[Rich Ullsmith]

I ask because I am in a situation where I am storing quite a few mounted prints in less than ideal conditions. Mainly temperature; down to about 55f. No corners have lifted, but I swear on one particular 16X20 there is a 1/32 inch strip of dry mount tissue exposed at the top that I had not noticed before. Could the print contract that much without releasing?

Any insights would be helpful. Or maybe not, as I really cannot change my storage situation. The prints are stored flat, and temp changes back to something closer to 70f will not be rapid.

 

[Konical]

Good Evening, Rich,

My first suspicion that any contraction would most likely cause a bowing in the print/mat sandwich rather than any "slippage," unless there is a waste print or a blank sheet of paper mounted on the back of the mat board to counter that possibility. I assume you're describing FB paper here?

Konical

 

[Rich Ullsmith]

Well, it can't bow because the one I describe is still framed but not that I look at others that are stored, they seem fine. All have been mounted 6mos to a few years. When many were shown, it was relatively hot and humid, and now in storage it is cool and humid. (NW Washington humid, not Bangkok.)

I think I just missed that strip of mount tissue before I framed it, more I think of it.

 

[Vaughn]

My guess -- you just did not notice the 1/32 inch of drymount tissue before, but it has been there all the time. The drymount tissue is dimensionally stable. Once properly mated, the print is permanently attached to the drymount tissue -- there can be no slippage if it still actually attached.

Most likely scenerio is that you did not pre-dry the print the print before attaching the drymount tissue and trimming the print/drymount. Then when you put the package into the mount press, the print was dried by the heat and it shrunk a little before becoming permanently adhered to the drymount tissue. Fiber paper tends to shrink more in one direction than the other, thus that 1/32" shows up on one side after drymounting. Unfortunately for us, "air dry" is not very dry...so I always put the mat board in the mount press for a minute then open and close the press several times to drive out the moisture. Then I put the print in with the mat board (in the mount press) and repeat. Now both are dry and I attach the drymount tissue to the print, trim, and then drymount it to the mount board.

Storing in cool temp is optimum...unfortunately for you (and for me in coastal Humboldt County) humid and cold is not. For us, the best thing to do would be to store our prints in a semi-sealed container with those containers of moisture absorbing pellets (sodium silicate?) and occasionally toss the containers of pellets into the oven to dry them out. I guess our other choice is to have a small room to store our prints and camera gear and run a de-humidifier in there on a regular basis.

Vaughn

 

[Rich Ullsmith]

Vaughn, I think the part about drying the print in the press before tacking the drymount tissue on and trimming, that is it because the only time I have ended up with a tissue extending is on the large prints. Bigger print, more contraction . . .aye.

Hee hee, of the thousand ways to screw up, maybe you helped me cross off number 492.

 

[Vaughn]

Then #496 must be having ants nest in one's print boxes while they were stored temporarily in the garage because one just moved. What a mess!

I still much prefer to dry mount my 16x20 silver prints (and "floated" in a slightly larger window mat), but now from personal experience I know why museums prefer prints not to be dry-mounted!

Vaughn

 

[Larry Bullis]

I think Vaughn's got it.

I'm in NW Washington, too. I use a similar method of pre-warming. An additional factor: some papers are especially susceptible to absorption of moisture. Ilford FB Warmtone is one. I've found that repeated gentle warmings rather than a single hot squashing may be necessary to keep the emulsion, which is soft, from sticking to the cover sheet. It's easy to end up with a defaced surface, but if sufficient care is taken, it can be avoided.

I have had this same result, and actually got rather good at removing the excess tissue carefully using a metal straightedge and a razor blade. The heavy bar the printmakers use, a "bevel bar," is best because it's heavy enough it's less likely to slip, but I've never been so fortunate as to have convenient access to one, so I use a good quality stainless steel graphic arts straightedge. Once the tissue is cut the full length of the print, it is easy to slip the blade under the tiny strip and lift it; it will pull right off.

Dry mounting still produces the best looking print, it seems to me. I've been trying NOT to do it in case my prints could be a resource for my family after I'm gone (how likely is that!), but I really don't like the way FB prints resist lying flat when treated as if they were etchings, etc.

Vaughn, do you leave a white border on your prints which is partially covered by the matte? I understand that air stains (those iridescent ones that we see on antique prints) begin at the edges and progress inward from there. Leaving about 1" of border around the print supposedly helps avoid that (but I ain't gonna be here when my prints start to airstain!).

 

[Rich Ullsmith]

That floating effect is something else, if there is an angled light source, like the bedlamp. Print looks like it's 1/8" off the board, with the shadow effect. I think it's unbeatable. I like a narrower border between print and overmat, 1/4" for small prints and 3/8" for large, it is quite an effect.

I have not heard of airstains before. Chances are the prints were left in a room before the paint dried on the walls, or something of that nature.

 

[Larry Bullis]

I have not heard of airstains before. Chances are the prints were left in a room before the paint dried on the walls, or something of that nature.

The air is full of chemicals. Always has been, especially since the beginning of the industrial revolution, and now, it is very bad; of course, in some places more so than others. The stain I'm referring to seems to be dichroic.

 

[Vaughn]

...Vaughn, do you leave a white border on your prints which is partially covered by the matte? I understand that air stains (those iridescent ones that we see on antique prints) begin at the edges and progress inward from there.

Very true, but again, I'll let my great great grand kids worry about that...so no, I trim the print right to the image. I do this only with silver gelatin prints. In the frame, the potential for air born damage is reduced -- especially with buffered board, and a piece of foamcore board behind that. Between the glass and the foam core, and the mount tissue behind the print itself, pollutant migration to the print is very slow...especially for us lucky enough to live in relatively clean air (we still get air blown in from China!)

With RC prints it is actually good to trim some of that white border off -- chemicals during processing migrate into the cut edges where they are very difficult to wash out -- and they don't get washed out with the short wash times one uses with RC. If you soak a RC print for too long the edges get wavy -- that is moisture trapped between the layers of resin.

Vaughn

 

[Larry Bullis]

...Between the glass and the foam core, and the mount tissue behind the print itself, pollutant migration to the print is very slow...especially for us lucky enough to live in relatively clean air (we still get air blown in from China!)

Fortunately, by the time it gets to Humboldt County, that Chinese air has been pretty well scrubbed!

I prefer to trim to the edge also, because signing on that baryta surface presents some problems. Signing on museum board is easily accomplished with a graphite pencil.