While in Grezzo I used the house to make a series of 1:1 cyanotype prints of the sunlight as it entered and moved around the house.
This first test did not work as the exposure was too short. I calculated that sunlight moves 15° every hour, or 2.5° every 10 minutes. I therefore needed to ensure that in the ~10 minutes exposure required for a cyanotype there was sufficient sunlight reaching each exposed part of the paper.
The next test was an exposure of ~11 minutes [14:38 – 14:49]. The paper was an A4, 120gsm Fabriano Drawing Paper, coated using a brush. The paper is really too light and gets saturated.
The next exposure was ~21 minutes [15:36 – 15:57]. This indicated that the length of exposure needed to obtain a good depth of cyan is approximately 5 minutes of strong sun.
This test placed the paper on the back of the shutters, which only receives diffuse, rather than direct sunlight as the shutter louvres are angled downwards.
Exposure: 16:04 – 16:24 [20 minutes]
The pre-wash exposure (left) was very successful, but once developed it lost all of the colour.
A longer exposure (times not recorded) produced this result.
A repeat of the above experiment left the exposure for several days, during which it was exposed to a rainfall. The extended exposure was much more successful, and while not intended the rain’s washing away of some of the cyanotype chemical recorded that event as well as the sunlight. This print was made on 200gsm A3 Fabriano paper, brush coated.
Exposure: 17:02 – 17:38 [36 minutes]
Exposed sheet before and during development.
Exposure: 17:59 – 19:27 [1hr, 28 minutes].
While this looked good during the exposure, and pre-development, the duration of each slim strand of light was not sufficient to adequately fix the image.
Exposure: 18:21 – 18:47 [26 minutes].
Sheet post-exposure (left), during development (middle), and the final print (right). Despite deep blue showing in the exposure most of this was lost in the development.
Double exposure. Due to the faint result of the last wall print I tested making a double exposure on the same print.
Exposure 1: 18:44 – 19:02 [18 minutes].
Exposure 2: 19:04 – 19:24 [20 minutes].
The two exposures are clearly distinguishable in the final print.
Door print. Exposure: 18:47 – 19:32 [45 minutes].
Exposure: 16:23 – 17:01 [38 minutes].
Exposure: 17:08 – 17:23 [15 minutes].
Exposure: 17:37 – 17:47 [10 minutes].
Exposure: 17:55 – 18:20 [25 minutes].
This print is made from 12 sheets of the A4, 120gsm paper. It is the first test for much larger prints, which I would like to be able to fill entire walls. Exposure: 18:30 – 18:47 [17 minutes].
After exposing and before developing, the backs of each sheet were numbered, so that the composite print could easily be reassembled. As the developing “bath” was a re-purposed IKEA drawer sitting in the shower tray I could only develop 2 sheets at a time.
As the paper was the lightweight version the resultant prints are uneven in the cyanotype coating, and quite wrinkly, even after ironing. The print was pinned up in its original location (which had been marked on the wall), and the sun repeated its journey over its earlier trace.
This last print was made after I had exhausted my supply of the 220GSM paper, and decided to test using some of Alex’s roll of detail paper. Exposure: 18:09 – 19:14 [1hr, 5 minutes].
Washing the print to develop it was challenging given the length and sheerness of the paper.