Fiber Print Drying Part 2: Extending to Larger Paper (12x16")

Last June I described a method of drying fiber prints using some simple and cheap Plexiglas or Perspex parts. The drawback is that they must be sized for the print. I modestly started then with 8x10 prints and had 4 sets of the dryers fabricated. They use a simple clamping method using bulldog clips. It was quite successful and I have used them many times since on my 8x10 FB prints.

At the time I promised to extend this to 12x16" which is the largest print size my darkroom is set up for. One reader commented about some problems they had with a similar approach.

Interesting method, Tried something similar with wooden blocks and bolts and wingnuts. 12 x 16 sometimes sheared off the edges of I started with a print that was too wet. Curious to know how you fare. 

(Update: I have added 16x20 to my repertoire now successfully.)

So I went back to the same manufacturer with an order that was a directly scaled up version of my 8x10 version. Below are the dimensions I used. The baseplate is in blue, the gray area is the print area without the 4 mm border of the paper which is covered by the clamp blocks. The clamp blocks are shown pulled away on the top and right and in-place on the left and bottom. The paper is 305x406mm when dry.

I used Foma  FOMABROM Variant IV 123 paper for the first prints I tried. (A lovely paper by the way.) I did the same method and number of bulldog clips to clamp the paper down. This meant crucially engaging the full throat of the clamp which meant the clip bore down directly on the narrow edge of the paper. On my first attempt this resulted in similar but not so catastrophic results as the reader quoted above. In the corners some of the paper had small tears and there was a little folding/puckering or distortion.  Needless to say I was disappointed. See examples below...

Small tear in corner of print

Minor folding and distortion

Larger tear

Tearing and folding/puckering

Puckering and folding 

The larger paper, as it shrunk, was generating more force as it dried than with 8x10 the dimensions being twice as long. I was left discouraged and did not pick up the subject for a couple of months until I found myself wanting to do some 12x16" FB prints again however and decided to pick up the subject of flattening them again. I reasoned that perhaps I had clamped too hard. The system works I think because there is a natural balance between the paper shrinking which pulls it taught between the clamped edges and at some point if this becomes too much the paper must either slip a little under the clamp or tear. Hopefully there is a wide latitude between these two points otherwise the setup would be too fiddly and not reliable.

Below is a timelapsed video where you can see this occurring. This is 30 minutes of drying collapsed to about 3.5 seconds. Look carefully at the margin at the left hand side.


Test paper shrink 3.4 sec from Doug Morse on Vimeo.

So on my next prints I tried clamping with the throat of the bulldog clips less engaged and the edges of the clips nearer the outside edge of the clamp blocks. This is exactly what was needed. I dried a series of 6 prints successfully with no tears or pucker. To be clear I used a different paper this time (Ilford MGIV Classic FB) but both papers are double weight. The Ilford paper is actually lighter weight at 255 g/m2 vs 280 g/m2 for the Foma. So I am confident it will work on the heavier Foma paper. The prints I flattened this way are featured in this blog post.

The steps are as follows. Here is a video of the process and below that some more explanation.


12x16 drier video from Doug Morse on Vimeo.

Step-by-Step

 Assemble the different parts as shown below. The base-plate or baseboard, the clamp blocks and bulldog clips.

All the parts are shown here. 

The print has been hung to dry after the final wash. Most of the surface moisture should have drained away but the fibers of the paper should still be wet and the paper floppy. This allows sufficient moisture present to allow for the shrinkage to occur. 

The wet print is centered on the baseboard.

Centering Print on Baseboard.

The clamp blocks will be arranged as shown below over the print when it is centered. They must overlap the margins of the print by about 4mm. It is alright for the clamp blocks to overlap the baseboard as can be seen on the lower right.

Clamp Blocks are in Place

 My earlier woes with tearing and buckling happened because I clamped the print as shown below. Here the throat of the clamp is fully engaged and the edge of the bulldog clip exerts all its pressure over the margin of the print. The means the paper cannot escape as it shrinks and tears rather than slips under tension.

THIS IS THE WRONG WAY TO APPLY THE BULLDOG CLIPS!

Below is the proper way to apply the clamp well back from the print margins. This supplies sufficient pressure to keep the print in tension. 

The correct way to apply the clamps. 

Here all the clamps are applied. Note how they exert pressure on the middle of the clamp blocks in all cases. This may now be propped up against a radiator or left in the sun for more rapid drying . Typically a half hour to hour is required. 

Clamps applied and ready for drying

Now the clamps are removed whne drying is finished and the paper comes out flat. 

Clamps removed and print removed from baseboard

Flat Print!