Meeting 13

One print due at the beginning of class. Critique of work.

Print mounting and matting methods.
Print flattening, dry mounting techniques demonstrated and discussed.

Print Flattening
Fiber prints don't dry flat unless they are dried in a blotter roll or a heated print flattener (seldom seen anymore). I air dry my prints between fiberglass screens to prevent large curls from appearing, but they still aren't acceptably flat.

To flatten the prints, I use a heated dry mount press (see the section below for more information about dry mounting presses). The prints should be fairly dry to begin with. Never try to dry damp prints in a dry mount press - the gelatin surface may become damaged because it may stick to the board above it! They shouldn't be too dry either because forcing brittle-dry prints flat may crack the emulsion. Be careful in extremely dry winter months. The humidity in summer shouldn't cause a problem.

I insert the prints between two sheets of mat board to prevent the picture surface from contacting the bare metal to of the dry mount press. The boards provide a path for humidity in the print to escape. I use about a minute at 100C (212F) to flatten the print.

When removed from the press, they will almost immediately start to curl again, so place the prints under a heavy flat object to cool. I use a piece of 11x14 plate glass for 8x10 prints. I use it also for my contact prints, so it's always handy.

If I have a number of prints to flatten, I repeat the process, and stack them together under the cooling glass.

There may be a little residual curve after flattening, but it's not nearly as objectionable as wavy air dried prints. If flatter prints are desired, read about dry mounting below.

Student research tip:
In winter, prints dry very brittle and can be damaged by forcing them flat either by hand or in a dry mounting press. The emulsion sometimes cracks.

It has been reported by an enterprising student that if a very dry print is first wiped with a moist towel on the back side of the print, it relaxes enough to permit flattening without cracking.

In thinking about this process, it would be important to avoid cheap paper towels because they could transfer acid into the print and shorten its life. Wood pulp, commonly used for the paper ingredient in paper towels, may not be treated to reduce the lignin-produced acid. Clean cotton would be best.

Dry Mounting
Overview of the Dry Mounting Process
Dry mounting is the process where a photograph is adhered to a backing board using a heat activated adhesive. Stiff mat board is generally used for the backing material. When attached to a flat board, reflections from a normally wavy glossy photographic surface are reduced. Because few processes outside photography produce glossy surfaces, you won't see dry mounting used with, say, watercolor.

In addition to the photograph, dry mounting requires dry mounting tissue, mat board, a paper cutter, a tacking iron, and a dry mount press. The press can be rather expensive to purchase. Some older textbooks suggest that a regular clothes iron may be substituted, but I had erratic results with one before I purchased a real dry mount press. If I were to try a clothes iron again, I'd be sure to sandwich the photo between two heavy 4-ply sheets of mat board to more evenly distribute the heat from the iron.

A company called Seal/Bienfang makes dry mounting presses in the U.S.A. I have a small Seal 110S press that can mount 11x14 prints, but I've done 16x20s with several overlapping "bites" in the press. Larger presses get very expensive.

I use a Seal tacking iron with a thermostatic control. A less expensive model has a fixed heat setting.

Seal /Bienfang makes several varieties of dry mount tissue. Their Colormount tissue has an adhesive that activates at a lower temperature making it the choice for RC photo papers. ArchivalMount is a type designed for fiber based photo papers, but the adhesive activation temperature can melt the plastic surface of RC prints. These tissues come in packages of various sizes.

I use acid-free mounting boards for the substrate. I have adopted a process where I dry mount my photos onto a sheet of 2-ply board, and then sandwich the mounted print between two pieces of 4-ply mount board, one of which has the opening cut for the picture.

For ~8"x10" prints, I use 11"x14" 2-ply mat board onto which I mount the photo. I place this in a window mat of 14x18 inches.

Dry Mounting Steps
First, clean your workspace! If there are any small bits of paper dust or other debris, they will find their way to your print. This debris will wreak havoc on the surface of the mounted print.

I begin by placing the print face down onto a piece of mat board, and lightly tacking the center of the tissue onto the back of the print. A small "swipe" about an inch or two in the center of the print will suffice. Test adhesion by lifting the print by the tissue. It should hold.

Use a paper cutter (Rotatrim, Premier, etc.) to trim the edges of the picture and the dry mount tissue. After you have done all four sides, the photo and the attached tissue will be exactly the same size.

Position the print onto the 2-ply mat board. I make sure that left and right margins are exactly the same, but just eyeball the top-bottom margin. I generally give the bottom a little more space to give a little room for the signature and title line later on. While securely holding the center of the print, lift one corner and tack the dry mount tissue found underneath to the mat board.

At this point, the print will be positioned onto the backing board. I lift the loosely held assembly, and gently blow between print and mat board in a last ditch effort to remove any bits of debris. Left behind, the small bits will be trapped between board and print, and will cause a visible bump on the surface of the print.

In the warmed-up press, place two sheets of clean mat board. Dry them by closing the press onto them for a minute. Do this a couple of times to make sure you have driven out moisture. Insert the print+ dry mount tissue + mat board between the two sheets of mount board - like a sandwich - and position everything in the press. Close the heated press for about a minute to sufficiently heat the tissue. The heat activates the adhesive within the tissue and bonds the photo to the backing.

When time is up, open the press, remove the print mounted to its board, and press it against a flat surface to cool. I have a large steel plate that absorbs the heat, but just pressing it onto a tabletop is sufficient. After a few seconds, test the adhesion by gently flexing the board with the attached print. Avoid severe flexure because that will surely break the print from its backing.

At this point, I sign the board just underneath the mounted print. This gets placed into a window mat "sandwich" in the next series of steps detailed in Meeting 15.