Drying and flattening larger fiber and RC paper

[Kornscharfsteller]

I am about to print my first 4x5 negatives and some of them I would like to print on larger fiber based paper at 50,8x61cm (20x24“) and some using RC paper of the same size.
So far I have only printed on smaller RC paper. I don’t have any experience in printing on fiber paper and also never printed this large at all.
How do I dry those large sheets and how do I flatten those fiber sheets? Does it make a difference whether the surface of the paper is glossy or not?
I do own a small darkroom (about 16m²) so I could build or install stuff in there as long as it doesn’t break the bank.

[jmdavis]

16 sq. m is about 4x the size of my darkroom. Flatness will partially depend on how you dry the prints. I use screens at home and then flatten in either a blotter book or the drymount press without heat. At the community darkroom, I dry on screens, then they go into a blotter to be flattened at home.

[Kornscharfsteller]

What do you mean by “screens” and is this a “dry mount press”:



If you use them without heat how long does it take to dry it? They can only take two prints, so that would be a veeeety slow process, if I could only print two sheets a day or so.

[Greg Y]

When we say 'screen' these are mesh screens in frames.....used in windows (in N America) to keep out flies. The device you show is a heated dryer. A drymount press is a device like this ... which is used in attaching prints to matboard. They come in various sizes....and are quite expensive. When using a drymount press, you dry the photos face down on screens and when they're dry, you flatten them in a (heated) drymount press for about 2 minutes. Fiber based papers do not dry flat. Some others here may comment on how to flatten FB prints without a press, but i've always used a press. ......but in my darkroom i have 2 rooms, one with enlargers and processing sinks, and another room for mounting, matting & storage.

[Drew Wiley]

20X24 isn't all that large. Easy. I air dry prints on clean fiberglass window screens, then put them under a big sheet of plate glass for flattening. I don't like to force-dry any kind of print, except for test strips. RC coatings will actually blister or melt if overheated. That strange device in the picture above looks like how they would have done it in a Neanderthal cave, just in case one of them invented photography as well as electric circuits too.
You might be able to cook waffle batter on it. ... But a screen is just a simple fiberglass screen material surrounded by air. For really big prints I use sliding patio door screens. Just order or make something slightly larger than your own print sizes. With multiple screens, or one big one, you can air dry as many prints as you want at a time. A drymount press is something entirely different, and could hypothetically be used for drying prints if you're careful not to overdo it, but are high wattage devices expensive to run for that kind of purpose. Besides, I wouldn't want anything wet in mine. It has another purpose : DRY-mounting per se; rust unwanted.

[Greg]

My prints are air dried on fiberglass window screens. Once dried I have two 24" x 36" flat countertops and place the dried prints between 2 ply archival board in between the countertops. The four 25 pound weights go on top. Usually takes about 24 hours for the prints to pretty much flatten out.

[Kornscharfsteller]

My prints are air dried on fiberglass window screens. Once dried I have two 24" x 36" flat countertops and place the dried prints between 2 ply archival board in between the countertops. The four 25 pound weights go on top. Usually takes about 24 hours for the prints to pretty much flatten out.

That works for fiber paper too?

What is „ply archival board“, sorry I am German and not a native English speaker.
Is this board similar to that what is used to make passepartouts?

[Drew Wiley]

Yes, screens are fine for drying fiber-based print too. But "2-ply, 4-ply,8-ply" refers to the thickness of the mounting board. "Archival" refers to its alleged properties protecting a print over a long period of time. In other words, it refers to the kind of backing board used to mount prints on, like when using heat-activated dry-mounting tissues. There is no need to use archival board like this for flattening if you are using something inert on both sides like plate glass instead. In fact, mounting board or matboard is probably not a good idea because it's hydroscopic and absorbs humidity, and doesn't lie totally flat itself. It's a paper or linen material. Both sides of the sandwich should be inert, both chemically and with respect to moisture. Most RC prints lie flat on their own after drying. That's because they have a thin plastic film on both sides. But fiber-based prints tend to curl upon drying.

[Pieter]

The first image you posted is a print dryer, the kind that was used by photographers for glossy fiber-based paper, producing a high-gloss glaze by squeegeeing the prints face-down on the polished metal surface and stretching the canvas across the top to hold the prints in place. The prints will release from the plate when they are dry, maybe 10 minutes. I don't think anyone uses them anymore, but I would guess if you have access to one and it heats up, you could give it a try. And 2-ply archival board refers to mount board that is 2-ply thick (maybe 2-3mm?) and is acid-free so no acid is transferred to the print that could cause discoloration in the long term.

[Jim Jones]

Kornscharfsteller -- Dry unmounted fiber prints that are stored face-to-face and back-to-back, perhaps under moderate weight, will flatten over time.