There are so many variables in making cyanotypes.  With the help of all things photographic guru David A., I devised a way of controlling the time that the images are exposed to UVA light.  

If my exposure of 1/15th sec on my camera = 4mins under UVA (because that is what I determined at the start of my experimenting)  then 1/30th sec = 2 mins under UVA.

If everything else was equal, then that would logically follow.  But it isn’t.

The variables which get in the way are: 

  1.  How long the hydrogen peroxide has been exposed to the air – the longer it stays, the more oxygen it has absorbed from / has given up to the environment and so the weaker its effects = the lighter the final ‘cyanotype  blue’ it is.
  2. How long the cyanide mix has been standing – the longer it stands, it seems, the more exposure time it needs – I haven’t worked out why yet.
  3. I had forgotten that for our cyanotype training last year, we had to take 2 copies of the digital negatives to make the resultant cyanotype clearer.
  4. The accuracy of the timing device.
  5. If I paint the cyanide mix onto the cotton, it dries blotchy but smooth.  If I soak the material in the cyanide jar mix and squeeze out the excess liquid, it dries creased.
The cyanide-soaked material on the top left was mixed 4 weeks ago.  The one on the top right was mixed today.
this print was made with the original cyanide mix 
and exposed for 4 mins.  I judged it too dark.
Same time exposure but different hydrogen peroxide freshness: left old HP , right: New HP
Camera exposure: 1/40th sec and therefore should have had 2 mins (right) I redid it but increased the timing to 3 mins (Left)   HP was newly mixed but still the old cyanide mixture.
Rosemary success: 1/15th: 4 mins.
Red cabbage: 1/15th sec: 4 mins.

The last 2 examples look much better in the photo than they do in reality.  maybe I’m just picky & want it to look like the design I made in Photoshop?

I found the time dial on the UVA lamp very crude: I could not get 2mins 30 secs but had to guess so I started using the timer on my phone.

The fennel has come out quite well:

Again, exposure time was critical here: top fennell I used the lamp timer; the bottom one I used my phone set at 2mins 30 secs.


Rabbit left: old stock of everything and 1 digital negative: 3 mins exposure.
Rabbit right: new stock of everything; 2 min exposure.  L = too dark; R = too light

6 thoughts on “Progress on my quilt cyanotype experiments.

    1. The UVA lamp I am using ( a birthday present from Steve!!) is the 6 bar Efbe Schoff. I have increased the exposure time to 4 mins now & the results are much better. With 35 panels to make, I could not rely on sunlight at this time of the year. I met a lady recently at the local sailing club who has been making quilts all her life so she is going to give me a hand with that side of things when she comes back at the end of January.

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  1. That sounds very promising. I’ve been finding that just over an hour of sunlight works reasonably art the moment – but then one has to rely on the sun staying out for that length of time!
    Great that you’re going to have someone experience in quilt-making to help you out as well. Reminded me of the lovely novel I read “How to Make an American Quilt” by Whitney Otto.

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    1. Sue is going to give me the sewing info I need to cope with that aspect. I have just extended the ‘cooking’ time to 6 mins & it works like a dream – I might have to redo a whole lot of other squares!

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  2. I haven’t explored cyanotype printing yet but have always been intrigued by what I have seen others do. The logistics of getting all of your squared cooked to the same extent is just mind boggling though when there are so many variables.

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    1. It is! I have had so many failures! But, yesterday I had a lot of good ones – I increased cooking time to 6 mins across the board & tried to see where it failed & where the strategy worked – I hope to have an update this evening after I have done the last 3 squares ;))

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