Building a paper humidifying box
After reading Stan Klimek's chapter in Dick Arentz's new book on plt/pld. printing, I was fascinated to read how Stan humidifies paper with a hunidifying box.
Unfortunately details of how to build one of these wasn't given.
Has anyone constructed one? Being able to control paper humidy that precisely would be a God send, especially now in the middle of winter.
Even though I have two humidifiers operating in my darkroom my paper still feels too dry and doesn't coat nearly as well as I would like.
Ditto, in the summer here in Texas we have humidity out the wazoo, but in the winter time I could use some more....
Any suggestions on the topic would be appreciated.
Let's see what I've got in the magic trash can for Mateo!
Granted I havn't built one before, I'd imagine it can't be too much different from a cigar humidor, which I do have. Its basically just a cedar box with a wet sponge in it. You keep the sponge wet with water, or a water/glycol blend in order to maintain the proper humidity level. When the level starts to drop, add a bit more solution. Pretty simple.
I was doing some Ziatypes last week and I humidified each sheet which I coated during that session for 1 minute and 40 seconds prior to coating. I mean, I held the paper about two or three inches from where the mist was coming out of the humidifier and then I moved the paper up and down along the long side of the paper and then turned the paper 90 degrees and did the same along the short side of the paper and this took about 1 min. 15 sec. For the remaining time, I repeated movement along the long side of the paper.
Originally Posted by donbga
I had no problems coating with the different solutions I used. The humidity in the house never got above the range of 36-41% during either of my printing sessions last week. I have more problems with cat hair getting into the printing frame. I noticed before I printed though.
I have not read the book, but I wonder if it is necessary to have a "high" degree of presicion when humidifying. I do the same, hold the sheet over the 10 dollar humidifier until it goes a little limp and I am done....so far I have not had a problem.
I sometimes wonder if we dont make things more difficult than what they should be.
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Originally Posted by colrehogan
I've got a mister that I use frequently with ziatypes, DOP palladiums and so on. My goal is to have a repeatable precise method as Stan implied in his chapter.
Perhaps I'll call him or e-mail and ask.
Well my goal is to make things easier and repeatable. I guess too much control can be over kill. Do you use mylar to protect your negatives?
Originally Posted by Jorge
I understand, but I think sometimes we loose track of the fact that the chemistry of these processes is very forgiving and that people doing them in the 1920s did not have humidifiers, destilled water, etc, etc...I think that as long as one remains consistent in the way we do things the results are always similar, if not exactly the same.
Originally Posted by donbga
As I understand it, and I could be wrong, I thought humidifying was necessary to obtain a smooth even coat, sometimes even with the magic brush I might get streaks if I dont humidify, so in winter when I print I humidify the paper, coat, let it dry and give it 5 minutes with a hair dryer and then print, no mylar.
But, I am doing DOP, I was a very successful failure at making zias, ruined more negatives than you can shake a stick at....
I haven't read what Stan wrote, so I can't comment specifically on the content, but I think there needs to be a bit of context taken with what he has written.
Let me first say that I think Stan is possibly the best pt/pd printer in the US right now. He is producing prints and getting image qualities out of his prints like no one else that I have seen. When I was at APIS two years ago, Dick Arentz and I were talking, and he commented on Stan's prints with very favorable sentiment.
Stan is printing commercially; for clients. This is the driving force behind an absolute level of consistency that he is striving for. When he does a print edition for someone, they probably approve a proof image printed in a certain way, with certain tonal qualities, etc., and if he were to then send them prints that have drifted a little due to humidity changes or temperature, etc., he would probably be getting rejections from the clients.
The critical nature of commercial printing for a client probably forces a huge amount of waste prints that never make it out of the shop, and he is doing everything he can to eliminate the variables to streamline the printing process.
I think it is fine if someone wants to bring pt/pd printing to the level of precision that can be expected with traditional silver processes, but that is not my approach to the pt/pd printing process. I feel that the variability of the process is part of the beauty of the effort, is very much a part of the nature of a hand-made print.
I limit the variability a good bit to ensure I am getting the representation of the image on the paper that I would like, but I do not make any attempt to eliminate it, because I feel that is a part of the process that helps make each hand-made print unique.
Now that said, you all have a RH meter in the darkroom, right? In the winter, I run humidifiers to get the humidity and temperature up to 70 degrees, about 50% RH. I won't print until it is over 40%, and under 60%.
I will pre-humidify the paper if necessary, and then leave it to normalize to the RH of the darkroom. This will normally only take a few minutes. As far as I'm concerned, if you can get the darkroom up to a proper RH, and keep it there, than there is no reason to build a humidor for your paper, because the darkroom essentially acts to do the same thing.
Don't expect a stack of paper in the drawer to be at the correct humidity, but if you pull out the sheets you plan to use that day and put them on your drying rack while you get everything set up, you will probaby be set to go without any delay. When they dry from the coating, they will reach a steady state condition near the RH of the room, so the paper will be consistent in humidity as long as you keep the room RH consistent.
Since I use the DOP process, this level of control is all that is required for my work. With POP, there is much more sensitivity to the humidity, so you either have to get very precise with the controls, or you have to live with the variability built into the process.
There are lots of "classic" humidifiers printed in various books. They all consist of some kind of box, a lower compartment of which contains a supersaturated solution of some chemical. This compartment has a lid full of holes, and the paper is inserted/suspended in the top compartment.
Different chemicals give different RH, with perfect concistency and repeatability.
-- Ole Tjugen, Luddite Elitist