6/16/2014

Fiber Print Drying Method


I have recently started printing on fiber-based paper in the darkroom. I started with RC paper which has the great advantages of speed (lower fix and wash times) and it dries perfectly flat. My referred poison here is Ilford MGIV Deluxe. The reasons to move to fiber are based on the view that most 'serious' photographers in the darkroom use fiber for archival quality. RC works really well I have to say with the biggest hassle of drying prints flat not present. With Fiber paper the paper inevitably curls. It makes in difficult to mount and to store.

I did some research and ran across the usual suspects, blotter paper under stacks of books (can work but really flat prints take days in my experience), wet prints hung back to back (better than nothing), a dry mount press or print drier (serious money), and finally taping the print by the margins to sheets of glass using wet adhesive packing or watercolor tape.

The last one caught my eye. It is clever and uses the wetness of the print together with the shrinkage of the paper to achieve flatness against the glass. Many people in forums testified to its effectiveness. Alas this kind of tape is difficult to find now. There is another downside in that large enough margins have to be reserved on the paper to accommodate the paper tape. So I got to thinking of alternatives. I finally puzzled out a simple system of clamping the prints along the edge in a similar fashion. I also figured out how to make it relatively affordable and dead simple to put together.

I start with a sheet of Plexiglas or perspex and some large paper clips. The clips are the kind used to hold large documents together. They are used to apply pressure to just the edge of the print. The wet paper is placed in the center of the perspex sheet. The perspex sheet has margins equal to the 'reach' of the clips. 4 clamp blocks made of perspex are arranged as a kind of border to the print and overlap the edge of the print by about 4mm when placed flush with the edge of the main sheet pf perspex. The large clips are now arranged around the outside of the border and the clamp blocks secure the edges of the print. Now the print dries as almost the entire surface is exposed to the air. Since the edges are clamped the paper shrinks in tension helping to keep it flat. The perspex I used initially is 6mm thick which works in the prototype.

Additionally it is possible to use this setup like a burnishing plate for glazing a print to a higher gloss. Placing the print emulsion-side down and carefully pressing the air bubbles out between the wet print and the perspex will result in a print with a very high gloss.

(This subject has been updated to include 12x16" prints now on a more recent post.)

My first prototype was for 8x10 prints. The dimensions I used are as follows. This allows a 4mm overlap on the print for the clamp area and works with 50mm (2in) clips as clamps.

Dimensions for 8x10 drier.
The print is represented in white in the center of the drawing. The baseplate is in blue under the print. The purple on the left is the long clamp block while the green is the short clamp block. There are 2 of each size of the clamp blocks with the right and top not shown here.

The parts I got made at an on-line perspex cutting service. There are many vendors about but you should shop around. There are a wide range of prices and shipment costs. I paid about £37 for a set of 4 8x10 driers without shipping at http://www.acrylic-online.co.uk .  A set of 12 clips at Staples cost me about £5. That was enough for 2 driers.

Example of the kind of clip I use
Step-by-Step

There are two versions of the explanation . A text and photo version below. and a video here...



Fibre Print Flattening from Doug Morse on Vimeo.

First I use the clamp blocks as a guide for positioning the print on the baseplate. I place the clamp blocks so they overlap the edge of the baseplate by about 4mm. I then lay the wet print against the two edges as closely as I can. It is possible to use the clamps at this stage to secure the clamp blocks if they shift while lining up the print.

Using clamp blocks as guide for positioning the print. 

Detail of the alignment step. 
 The next step is optional as some people object to the use of a squeegee on a print. This helps accelerate drying but is not necessary. You should make sure in this case the print has dripped dry sufficiently that pockets of water cannot form under it.
Squeegee the print. Note blocks have been shifted to overlap the border of the print. 
Next all the clamp blocks are positioned to be flush with the edge of the baseplate. There should be a margin all around the edge of the print that is covered by the clamp blocks. If this is not true the print was not positioned properly.
Position clamp blocks flush to the edge of the baseplate. 
 Now it is ready to apply the clips. I use 6 for the 8x10 example here. This was tested on Ilford FB Cooltone paper. Other paper may require more clamp force and thus more clamps. More clamp force can be obtained by making the overall thickness greater as well with a board or sheets of cardboard.
Ready to clamp

Clamps in position. Note the top and bottom ones do double duty of clamping more than one clamp block. 

The Dried Print






5 comments:

simon hall said...

Thank you, this is brilliant. I've been hanging my prints back to back which is OK but not great. This looks like the perfect solution.

Is there any reason you couldn't put a print on each side of the frame if you had larger clips that could accommodate the extra width?

MorseBlog said...

Thanks you. Yes I thought of putting another print on the other side but didn't try it. The reason is that I thought that I would tape the clamp blocks to the main sheet as a sort of hinge to keep it all together. But if you didn't mind not doing that I see no reason it shouldn't work.

I want to try it on 12x16 next.

naaldvoerder said...

Interesting method, Tried something similar with wooden blocks and bolts and wingnuts. 12 x 16 somethimes sheared off the edges of I started with a print that was too wet. Curiious to know how you fare.
Do the acrylic blocks not leave a imprint in the paper's edges?

MorseBlog said...

I was thinking at first about using wood blocks too. I guess I got lazy when I realized I could get someone else to to the work. When I build the 12x16 version I'll post the results. Makes sense there is more risk of tearing as the force of the shrinkage is probably proportional to the dimension of the paper. I expected the paper to slip too easily when I tried this the first time.

The block make an imprint that results in the border being more glossy.

MorseBlog said...

As I mentioned I finally got around to updating the subject to 12x16" prints. See this entry here... http://remorseblog.blogspot.co.uk/2015/03/fiber-print-drying-part-2-extending-to.html