Isn’t this stuff supposed to be simple?

Cyanotype Emulsion tests

Sometimes things work out and I barely even need my test strips.  Other days, I want to throw my head back and howl with frustration.  

My last batch of prints weren’t even printed – I pulled the paper out of the bags and realized that it was a beautiful bright blue.   That was to be my test batch of sized paper with a double coat of emulsion.  Somehow, something happened to fog my paper in a spectacular manner.    So… I set out to eliminate variables with a batch of test prints on a negative that I know prints well, but prints some wonderful deep blues.   I was almost out of emulsion, so I ended up mixing a new batch to see if it was a chemical problem. 

All 4 prints are on Canson Montval paper, printed at 8 minutes exposure in full sun. 

  1. Single coat of new emulsion
  2. Double coat of emulsion. 
  3. Sized with Arrowroot sizing, single coat of emulsion. 
  4. Sized with Arrowroot sizing, double coat of emulsion.

  

I didn’t include any pics of the old emulsion because they were horrible.   Apparently the old emulsion was the source of my highlight issues from earlier.   

  1. Print #1 did ok.  The highlights cleared fairly well and the blues were deep.  Paper texture is bad, with little fuzzy  white paper fibers embedded in the emulsion.  Lack of detail is also an issue.
  2. Double emulsions without sizing had wildly varying results despite every other variable (development time, vinegar ratio, etc) staying the same.  One print would be super dark and overexposed, while the next would be underexposed, or with purple highlights.
  3. Single coat with sizing did the best of the lot, despite some issues.  Deep blues, no paper fibers bumbling around, and some lovely shadow detail despite being extremely overexposed.  For some reason, this has super high contrast, most likely because almost none of the emulsion washes off.
  4. Fun, but not practical.  It does this odd, spattered look that looks cool if it happens in the right spots, but requires extra washing to get rid of the excess emulsion.  Nice deep blues.

  

So, after I figured out which worked best, I tested the negative exposure times and vinegar ratios, producing this. 

"Thistle," Cyanotype

This has drastically lower exposure times at 3 minutes, developed in a straight vinegar solution.   Much better detail than unsized paper, and a beautiful deep blue that should tone well, provided the highlights aren’t too muddy.

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