Re: Persistent cyanotype spots


Christina Z. Anderson
 

Thank you for the compliment, Cinda! When a book helps someone in their process, it is so worth it.

I collaborated on writing Cyanotype with Sam Wang, John Jackson, and Sandy King as we tested the processes back and forth for a year (truth be told, I had asked two other people to write that book and they weren’t interested, so that’s the reason I wrote it). I finally buckled down and bought a densitometer to quantify my findings; these three always used densitometers. Best purchase I ever made for alt. I am totally hooked on cyanotype after writing that book. It is such a stress-free process in a way, at a nickel of chemistry per print. In writing the book I solved so many problems with the process that I had noted in teaching cyanotype for 20 years. Paper speckles, print fading, spots, blah prints, too contrasty prints, etc.

If you are into cyanotype, you will be interested to know that the next book in the series is Cyanotype Toning, Using Botanicals to Tone Blueprints Naturally by Annette Golaz who lives in Switzerland. Annette has a unique writing style I don’t possess. Almost “melodic” in the way she weaves history first into practice and then directions. Very user-friendly, reads like a novel or cookbook. So there’s more cyanotype information on the horizon! It’s in copy edit stage now with expected publication summer or early fall I think (with covid all things are moving slowly).
 
Chris

On Feb 17, 2021, at 11:01 AM, Cinda Berry <Cyrreb@...> wrote:

Hi Christina,

Just wanted to say that I have your book and it is an indispensable resource.  

It is written so well and has so much good information that I was able to get some decent cyanotypes on the first try!

Cinda


On Feb 16, 2021, at 9:18 PM, Chris Seiberling, <christopher.seiberling@...> wrote:

 HPR — Hahnemühle Platinum Rag.

On Feb 16, 2021, at 7:18 PM, ender100 via groups.io <Ender100@...> wrote:

What paper?

Best Wishes,
Mark Nelson


Curve Calculator III for the Mac is Now Available

sent from my iPhonetypeDeviceThingy

On Feb 16, 2021, at 6:15 PM, Chris Seiberling, <christopher.seiberling@...> wrote:


OK, cyano-peeps… I’m at my wits end.

I’m getting persistent spots, roughly 1/2 an inch in diameter, in spite of what I understand to be the usual precautions.

  • I’m printing ‘New’ cyanotype on HPR; to the sensitizer I add 40% citric acid at 1:20 and 5% Tween at 1:30.
  • I’m prehumidifying for 24 hours— paper placed on nylon screen with polyethylene cover over water (which tests neutral pH).
  • immediately after sensitizing I hang the paper vertically for drying. I place a large tray with warm water on the floor immediately below the print to increase local humidity in case the sensitizer is drying too quickly. It’s taking less than an hour to dry.
  • the darkroom temperature is 59 degrees F; humidity is at 56%.
  • the spots are visible after exposure and before immersion in the first bath (1% sulfumic acid). The spots have no relation to the negative or printing frame.
  • Now, it’s true that I’m not getting spots in the summer with this protocol, even if the dehumidifier indicates 40%.

Any suggestions would be greatly appreciated!
Thanks, Chris Seiberling




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