Cyanotypes

            John Herschel (1792 -1871) was an astronomer who is credited as being the man that developed the cyanotype (blueprint) process after trying to find a suitable way to copy his notes.  He initially found that the early papers that were coated with iron salts and used in contact printing could be fixed using hyposulphite of soda, and then eventually the paper would then be washed in water and would in turn produce a white image on a blue background. Herschel was apparently also the man that gave us the words photography, negative,positive and snapshot.

                                              
                                             
                                                         Herschels 'Lady With Harp'


                In 1843, a British botanist Anna Atkins (1799 - 1871), became the first person to use cyanotypes to photographically illustrate a book that she had also produced. Her book of ferns from 1843 meant she became a figure of note in photographic history as she is now recognised as being the first person to produce a book using photographic prints. Anna's images were also known as shadowgraphs as they were produced by laying the ferns directly onto the sensitised paper prior to being exposed in the naturally available UV light (sunshine).

                                               

                                               Atkins 'Asplenium Marinium' 1853 

                     There is another image of note from an American artist called Henry Bosse that was printed in 1853 and is held in the National Museum of American Art called Mouth of the St. Croix River . Now I know how the basics of cyanotypes works but what fascinates me about this image is simply the way he has managed to capture a landscape in such wonderful detail, especially for the time it was produced although I can't say for sure whether this is the original or  a retouched image for the benefit of the viewer.

                                                     

                                                           Producing Cyanotypes

• knowledge of COSHH data sheet 
• ammonium ferric citrate
• potassium ferricyanide
• distilled water
• water-colour paper  
• chinese brush
• light-tight container
• ohp acetate
• cheap glass clip frame    

1/ Mix equal parts (25g) ammonium ferric citrate and potassium ferricyanide with 100mls of distilled water each.

2/ Mix both solutions together and keep in light tight container until ready to use, this is your sensitiser.

3/ Lay out a sheet of water-colour paper and try and ensure you keep it free from greasy finger prints and the like, apply a minimal amount of sensitiser to your brush and make sure you don't saturate it as you only need to apply a thin coat of sensitiser in even strokes onto the paper.

4/ Put the paper to dry in a dark drawer as will now be light sensitive.

5/ Using photoshop, find a suitable image that doesn't contain too many dark shadows or blown highlights and invert the image so that it resembles a negative.

6/ Print this image onto a sheet of OHP acetate making sure you print onto the rough side so that he ink sticks.

7/ When both the sensitised paper and acetate are dry, place the paper face up on the backing board of the frame, then the acetate on top and lastly the glass and clip it up to prevent it moving.

8/ Place outside in direct sunlight for around 5 minutes, you should be able to see the yellow turn a deeper green/blue but don't worry if you don't have bright sunshine as it will just require a longer exposure and if its raining a UV sunlamp will do the job although it may take around 50 minutes .

9/ Final thing to do is unclip and rinse the paper in cold water to remove the solution and prevent it from continuing to develop, this may take a couple of rinses but you should see all the yellow disappear and a nice blue print as a final result.

10/ Leave to dry .

                                                                    Results

For my first attempt I used a macro image of a decaying leaf as I thought it might produce some interesting results but instead it was left over exposed and so just became a blue/black abstract that wasn't even worthy of scanning but as I said, it was a first attempt so I thought I'd give it another go with a simpler floral image which you can see below.

                                                      

           Maybe not the most interesting of results but it did show the detail in the petals although I feel the background could have been with being a bit lighter. For my third attempt I used an old image I'd taken in Copenhagen as I thought it might work well but again I feel that it has too many shadows and highlights and my research I have done since, suggests that you should look for an image with less severe contrasts for better results.

                                                         

  

  

         Now I don't mind cyanotypes but I'm sort of in the mindset that unless the image chosen is spot on, then I could soon be bored of these blueprints and with this in mind I set out to see about what else could be done with them, which  is when I came across the idea of tea staining them. For this I just made a gentle bleach solution and washed the cyanotype in it brushing the deeper bits with my fingers to speed it up, I then rinsed it off and put it into a dish with boiling water and 6 teabags ...the tea doesn't have to be boiling, it's just I'm very impatient at times, then take it out and leave it to dry. I must also point out I couldn't wait for this bit either so I stuck it in the oven to dry a bit quicker and the result is below, but just try and ignore the fact he's walking the other way because I flipped the above image when I realised it looked better with the acetate on the left. 

                                                               

       

                                                              Conclusion

           Choose images with less of a severe contrast, be careful of over exposing, don't brush completely to the end of the sheet as it gives a much better effect if you can see the brush strokes on the edge of the frame and finally continue to experiment with things like tea to achieve a different set of results.