Art and Chemistry
- The magic of substances
- A Chemistry/ Visual Arts Collaboration
- Seeing the transformation
- Alternative Photography – The Cyanotypes (Prussian Blue)
- Part 1: In the Chemistry Lab
Most art processes rely on some kind of chemical substance. Oil paints are mineral pigments ground with special oils, diluted with turpentine (an essential volatile oil). Printmaking techniques, darkroom photography, even charcoal relies on the transformation of a substance ( wood, fire= charcoal)
Most of the time we are completely unaware of the chemical make up and processes at work when we are making art.
This practical activity outlined below is an approach to making images that relies on a chemical transformative process. It increases the art students' awareness of the importance of materials, reveals the role of chemistry behind art processes and the alchemical nature of artistic experimentation. This project requires a collaboration with the chemistry teacher and use of the lab. It is not difficult however, and produces reliably interesting results. It is also a great way to create connections between the subjects and at the same time generate some great material for process portfolio screens! I worked with my colleague Jana Krainova in the Chemistry department years ago on this collaborative project which we hope you will enjoy!
What is a Cyanotype?
Making a cyanotype print involves placing a negative image, either a photographic negative, or an object, as in a photogram — on paper or fabric that has been prepared with an iron-based solution. The paper with the negative image on it is placed under ultraviolet light, or in direct sun, to develop. When the desired "print" is reached, the objects are removed and the paper is rinsed thoroughly to fix the image.
Cyanotypes are sometimes referred to as a"Sun print" in that the final image appears only with the aid of ultra-violet, or sun light. The cyanotype process is about 150 years old. The colours can range in their final metamorphose from pale to deep blue tones and everything in between.
22.50g Ammonium Iron (III) Oxalate; (NH4)3[Fe (C2O4)3].3H2O
7.50g Potassium Ferricyanide; K3[Fe (CN)6]
3.75g Ammonium Dichromate; (NH4)2Cr2O7
Pestle and mortar, beaker, Bunsen burner, heating screen, stirring rod, thermometer, scales, weighing boats, funnel, filter paper, stand and clamps.
This work should be carried out under tungsten light, not fluorescent or daylight.
Please note that all chemicals are poisonous!
2. Heat about 25 cm3 of distilled water to approximately 50°C and dissolve in it 22.5g of Ammonium Iron (III) Oxalate.
3. Prepare 25% solution of Ammonium Dichromate by dissolving 3.75g of the solid in distilled water and making up to a final volume of 15 cm3.
4. Add 0.4 cm3 of Ammonium Dichromate solution to the solution of Ammonium Iron (III) Oxalate prepared in 2 and mix thoroughly.
5. To this solution while still hot add 7.50g of finely powdered Potassium Ferricyanide in small portions with vigorous stirring. Few ( or preferably no) red crystals should be seen and green crystals will begin to appear. Set the solution aside in a dark place to cool and crystallise for about an hour.
6. Separate most of the liquid from the green crystals by filtration. The green solid is disposed of safely! The volume of the solution extracted should be approx. 25 to 28 cm3.
7. Make up the olive-yellow coloured solution with distilled water to a final volume of 75 cm3.
8. Filter the sensitizer solution and store it in a brown bottle kept in the dark
Prepare all the paper you will be using for the prints, experimenting with different paper types. A textured heavy paper, like watercolor paper works really well. You can also print on cloth or wood. Prepare all the objects, or shapes you will use for printing first because the actual process all happens quite quickly.
You can also create negatives on acetate with a photocopier or drawing on acetate. As long as it is transparent to allow light through it will make an impression. This part of the process is actually the most creative part and requires thinking, planning, exploring ideas beforehand.
Try using objects that have perforations or meshes, or varying opacity for more interesting prints. A completely opaque solid object will just make a silhouette shape.
Have baths of water ready for rinsing off the chemicals, or basins in the sink.
Using a wide even brush, paint the prussian blue solution on the paper.
Arrange the objects you have chosen, or the image on acetate, on the still wet surface. (Glass or perspex sheets will aide in keeping the objects in place when making prints of relatively flat things, such as leaves . Heavier objects will weight the paper themselves)
Expose to sun light for a few minutes
After exposure carry the piece inside, remove the objects and rinse the paper thoroughly and leave to dry away from the light
Teaching Materials for this lesson
Cyanotype photography ppt presentation
Cyanotype photography pdf version
Apparently, cyanotypes are very trendy! Read this recent article in the New York Times Cyanotypes, Photographys Blue Period is Making a Comeback