Re: pyro and cyano
Hi Christina, 10 Nisan 2009, Cuma, 6:45 pm tarihinde, Christina Z. Anderson yazmış: > Bob, > I quit using the hydrogen peroxide because it was questioned to perhaps > compromise the archivalness of the paper and it was unnecessary because > the > print would eventually get to that dark blue anyway, PLUS it seemed to > bleach the print a bit, though this latter is only subjective to me and > another person or so. I don't think it will hurt the archival qualities of the paper if you use very little like a cap (5-10ml) into 1000-2000ml water, keep the bath sort (30-60 seconds is more than enough) and rinse well afterwards. That's what I do; I experience no bleaching at that concentration and timing... > BUT this is my question--does the hydrogen peroxided print actually get > darker blue than one that oxidizes over several days? So if it gets > darker, > there would be a benefit to it. I have not tested this. No it doesn't get darker. You just get the final result (w/o waiting a couple of days) as soon as the print is completely dry. > ... > Let me tell you, people complain about gum being fickle, I find personally > in my practice cyanotype the most fickle process of all. I can only chalk > it up to the fact that humidity and coating plays a way greater part in > that > process than people imagine. I know Sam Wang tames it beautifully. Just because of this, I think it's a wonderful process to enter the alt-process world. Everything else (well, most...) looks like piece of cake after being able to achieve consistent success with cyanotype. I was shocked to find out how pt/pd is so much easier compared to cyanotype, for instance! Maybe it's the other way; cyanotype tames the printer ;) > I also find that it is very unpredictable with my students in literally > every class I have taught on alt. Yesterday, one student used the same > neg > and curve and the print was completely overexposed and unusable. And I > know > he is not a student that would leave the lightbox on and go out for a cup > of > coffee. It was that way to me (unpredictable) until I finally realized that it was due extremely high sensitivity of the process to the ambient/paper humidity levels. Predictability/consistency came right after I decided to force dry (bone dry) the paper after letting it soak the sensitizer for about 10 minutes using a hairdryer at hottest setting and sealing the back of the paper using a mylar sheet while exposing it. Ta da! That was the trick for me. I haven't got even a single non-usable print after that. BTW, try to bleach the unusably dark prints in 20% oxalic acid (following a thorough water rinse) to salvage them... (This was mentioned somewhere in Mike Ware's book IIRC.) > But I am always combining cyanotype with another process, either gum or > palladium, the latter which I just love so I actually use it frequently. I > think I just need to really delve into Mike Ware's book. Yeps, so much useful info. I learn more every time I get it into my hands! Regards, Loris.
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