A few months ago, I posted some images from an 1803 botanical text book. Here. I didn’t like the way they looked, and knowing that I can’t leave anything in its original state, I started playing with them on Photoshop. I hit some button or another, and the prints were magically transformed.
I inverted the colours, so the blacks and greys turned into whites and light blues, and the pale yellow background turned into a dark blue-print or cyan blue. I think the detail of the engraving shows up a lot more on the cyanotype.
It turns out that there’s quite the history of cyanotype botanical prints, first rendered as prints of algae in England by a woman, Anna Atkins. She placed the specimen right on the paper coated with solution of potassium ferricyanide and a ferric ammonium citrate and let the sunlight do the work.
Where the algae was thinner, more light got through and where it was thicker, less light entered, so the paper stayed white. You can read more about Anna and the cyan process here. She published three volumes of British Algae, and each page in each volume had to be individually printed. All of the known copies are in museums and libraries now. However, many of the museums and libraries have digitized the images from the books.
The great thing about Photoshop is that you can play around with the images numerous times, but you should always save a copy of the original. Lighter background? When I do this, more of the shading and foxing on the paper shows.
It was fascinating to learn about cyanotypes, and to see what I can do when I play with Photoshop!