How blueprints work

• Sunny days have enough UV light. Cloudy days usually don't.
• Cyanotype paper is coated with two iron salts
• Where sunlight reaches the coating, the coating turns bronze-grey
• Where a plant blocks the light, the coating does not change
• Rinsing in water washes the unchanged coating away, leaving white where the plant was
• The parts touched by sunlight turn Prussian blue
• The sun creates the image.

Prepare coated paper

1. Prepare the workspace

• Work in a dim room with only indoor light, as dark as possible
• No direct sun, best after sunset
• Wear gloves

Prepare coated paper

2. Mix the solution

• Mix equal parts of A liquid (ferric ammonium citrate) and B liquid (potassium ferricyanide)
• Use the mixed solution right away, it cannot be stored for later
• You need 3 to 4 ml of mixed solution for one A4 paper
• Do not put it in your mouth.
• Wash your hands well if it touches your skin

Prepare coated paper

3. Coat the paper

• Brush the solution evenly onto watercolour paper
• Use the rougher side with texture, not the smooth side
• Take some photos of the process

Prepare coated paper

4. Clean the workspace

• Stains slowly turn blue in light and can be hard to remove from some surfaces

Prepare coated paper

5. Dry in the dark

• Let the paper dry fully, away from light, best during the night
• A little curling is no problem

Gather and arrange botanicals

6. Gather botanicals

• Use flat leaves, flowers, and thin slices of small hard fruits
• The print shows the shadow of each element, so choose shapes with a clear outline
• You can also collect botanicals and dry them in a book for a few days before using, especially those that curl
• Take some photos of the process, like the trees you take leaves and flowers from

Gather and arrange botanicals

7. Compose

• Work indoors, as dim as possible, away from sunlight
• Put thick paperboard down first, then the coated paper with the coated side up
• Arrange the botanicals on the coated side, see the gallery for examples
• Use each botanical piece only once, make every print with new elements and a new pattern
• Leave a little space between the botanicals, but no big empty areas, fill the whole paper
• Use short, thin tape to fix the stem or leaf in place if needed
• Cover with a transparent acrylic board
• Use clips to press all layers together, so that there is no gap between the botanicals and the coated paper, otherwise the print becomes blurry
• Take some photos of the process, like how you arrange the botanicals

Expose, rinse, develop, dry

8. Make a test strip

• It should be a sunny day
• Put a small piece of coated paper in the sun for 30 minutes, with nothing on it
• It turns bronze-grey, which means the reaction is complete
• This is the colour you want on the uncovered parts of your prints

Expose, rinse, develop, dry

9. Expose in the sun

• It should be a sunny day
• Exposure time depends on the sunlight
• Sunny days have enough UV light, cloudy days are not suitable
• The uncovered parts turn bronze-grey
• Take some photos of the process, like the surroundings of where you expose the print to the sun

Expose, rinse, develop, dry

10. Rinse

• Wear gloves
• Put the print in water until the yellow is gone and the blue appears
• Do not rub the paper: the yellow washes out by itself in a few minutes, the blue stays
• Use fresh water again if you still see yellow
• Take some photos of the process

Expose, rinse, develop, dry

11. Spray hydrogen peroxide

• The blue becomes darker right away; without it this takes several days
• Hydrogen peroxide is not toxic, but wash your hands well after contact

Expose, rinse, develop, dry

12. Dry flat

• Air-dry on a flat surface
• Keep away from direct sunlight, full darkness is not needed
• Take some photos of the process, like the surroundings of where you dry the print

Tag and record

13. Print tags

• Tags are printed the same way as the botanicals, but the pattern comes from a print on transparent paper instead of plants
• One A4 gives you 6 tags to cut apart
• Take some photos of the process

Tag and record

14. Record

• On each tag, write the maker, the plant type, and the date. You can make it more personal, for example: with a smile, with love, mother of three
• On the back of the tag, tape a piece of flattened plant with paper tape
• On the back of the tag, write "from the same tree/plant" and draw the Helia icon

Tag and record

15. Attach

• Tape 2 finished tags to the back of each A4 print with paper tape

Post-processing in the Netherlands

• Organizers and volunteers cut the final pieces from the A4, following the pattern and composition
• Each piece gets packaging with a unique ID, so everyone can trace where it comes from and where it goes
• All information and all further activities are shared openly