What you'll learn:
How to make Cyanotype sunprint paper at home for blueprints or fabric printing.
Not all chemical reactions happen when solutions are mixed - some occur with heat or light. Some chemical reactions cause visible changes.
Cyanotype sun printing is a great way to make use of the summer sun, and while you can purchase pre-made sunprint paper, these often come on very thin, very low-quality paper. Plus, if you get the two solutions that combine to make cyanotype prints you can do fabric printing too!
The process will combine two solutions that are non-toxic to the touch but should be used under adult supervision. We suggest using droppers or gloves and make sure that kids don't ingest the solutions.
You have likely seen cyanotype used in real life as it was often used to create blueprints, the architectural drawings with a distinctive blue color. Cyanotype solutions, ferric ammonium citrate, and potassium ferricyanide come separately and combine to form a light-sensitive permanent pigment.
When exposed, the UV light causes the citrate in the ferric ammonium citrate to give up one of its electrons to an iron atom that originally shared three electrons (which can be written as FeIII). This additional electron turns the FeIII into FeII, an iron atom that shares only two electrons. The new FeII now reacts with the potassium ferricyanide to create a permanent blue pigment called "Prussian Blue". That means this project uses the sun to begin a chemical reaction!
Below we will walk you through the process of making your own sun print paper or fabric to create your own unique cyanotypes as you engage in this fun chemistry meets art project.
How to make Cyanotype sun print paper
**SAFETY NOTES: The two cyanotype solutions do not pose serious health risks with the exception of very few who show an allergic reaction to the chemical compounds. Potassium ferricyanide should not be heated or mixed with acids of any type.
1. Reconstitute and Mix your solutions.
Cyanotype sunprints are UV reactive only after the two solutions have been mixed. The bottles you purchased online are already measured in terms of chemical quantities – which means you just add water to the container, cap, and shake to mix. Do this for each solution so you are prepared with a solution A and solution B. Since these chemicals are powders before being dissolved into water, we recommend an adult do this step.
Then you want to mix your solutions in a 1:1 ratio. An 8×10 final image takes about 40 drops total (20 of each solution). You can use this as a guide to determine how much of your solution A and solution B to mix together.
2. Prepare your paper
After you have mixed the two solutions together you will need to work indoors, away from windows. Once mixed the solution becomes UV reactive. That means regular room lights are OK, but anything with UV radiation will activate your art.
To prepare the paper put the entire amount of drops in the middle of the paper (40 drops for an 8×10 piece, 12 drops for a 4×5 piece). Using either a wet paintbrush that does not have any metal, a glass rod, or a plastic scraper, spread the cyanotype solution around the page from side to side. Do this quickly until you have covered your entire area. The solution should be spread, and absorbed, within about 30 seconds.
Allow the paper to dry completely in a cool area, again away from windows and also in a dimly lit room if possible.
3. Create your art
You can use anything to create your art, flowers, rocks, shells, semi-transparent scarves, keys, stained glass pieces, pencils, washers…the sky is the limit. This is a great chance to experiment with the idea of the opaque to transparent spectrum as well as to play with the effect of shadows.
Make sure that your objects are heavy enough to stay down in any breeze – we used some flower petals that just would not stay in place, which ended up being a source of frustration and a good lesson in thinking about practicality.
4. Set your art outside
It takes somewhere between 5-20 minutes for your art to become exposed to the sun. The amount of time depends on both the position of the sun in the sky, with early morning sun delivering a more powerful chemical reaction and the color of blue you desire at the end. The blue will get deeper and deeper as the exposure length increases. If you want deep blue images you need a longer exposure time.
5. Develop your image.
This step is used only if you want to stop the reaction of your art. This is useful if you have the design you want, but want to be able to expose the image to light in the future. To stop the chemical reaction prepare a bath of water with a few squirts of 3% hydrogen peroxide. When your sun art printing is complete bathe the paper in the water/peroxide solution. The water will turn a bit yellow as if finishes the pulls the unreacted iron out. You can make the bath clear again by adding more hydrogen peroxide.
6. Dry your art.
Dry your art in a cool dimply lit area. This will take about 20 minutes.
Take your Cyantype one step further!
Create your own sepia-esque blue-toned photographs with cyantype techniques. To do this you will need the negative image of your photo printed on an overhead transparency and a piece of plexiglass.
After you have prepared your paper place the transparency over the sun print paper and secure in place with clear plexiglass. You can also tape the overhead in place, however, this may show up in your final result.
Expose the paper to the sun for 20 minutes and develop it in the water/hydrogen peroxide solution as described above.
Fabric printing with the sun and cyanotype
You are not limited to watercolor paper for the creation of your cyanoprints. You can use this method for unique and creative fabric printing as well. In fact, this technique will work on any surface that absorbs an aqueous (water-based) solution.
To print on fabric spread your mixed, UV sensitive solution on the fabric or piece desired.
Overlay your art as described previously, expose to the sun for 15-20 minutes, and rinse as described above. I had my girls make a drawingin sharpie on an overhead transparency - this is a great way to make creative grandparent gifts!