Family Day HEK x KHBL: Sun Art

At the recent Family Day HEK x KHBL, we made the most of the last of the August sun and spent the afternoon making cyanotypes. Visitors of all ages experimented with the materials we had prepared, collected leaves and flowers, and created their own drawings on transparent paper.

We were also joined by artist Lena Laguna, who works extensively with cyanotype in her own practice. She shared her knowledge throughout the afternoon, giving visitors the chance to ask questions, try things out and learn more about the process as they worked.

Family Day with KBHL x HEK, 30.08.2026

Cyanotype is a photographic printing process that uses light to create an image. Once the prepared paper is placed in the sun, the exposed areas gradually turn blue, while the parts covered by objects or drawings remain pale. The result depends on the weather, the strength of the sunlight, the materials you use and how long you leave the print outside. That unpredictability is part of what makes the process so appealing: you can plan the composition, but the final image always has an element of surprise.

Studio Lemercier: Thesholds, Exhibition HEK

This interest in working directly with natural forces also connects to Studio Lemercier: Thresholds, the current exhibition at HEK. In recent years, Studio Lemercier has increasingly turned towards low-tech approaches and questions around energy, ecology and the environmental impact of technological systems. Rather than treating technology as something separate from nature, their work explores how natural forces such as sunlight and wind can themselves become tools, materials and sources of energy. This also raises broader questions about the technologies we choose to develop and the systems that shape those choices. Research into renewable energy has a long history, but its development has often been influenced by political and economic interests. Today, solar and wind energy play an increasingly important role, yet their possibilities are still far from exhausted. These questions are central to Solar Lab, a research initiative by Juliette Bibasse, Joanie Lemercier and Martin Pirson. The project explores how natural forces can be used not only to generate energy, but also as materials for artistic and creative practice.

Cyanotypie designs, exposure phase, 30.08.2026

Cyanotype fits naturally into this way of thinking. In their SOLAR LAB MANIFESTO, the artists describe Solar Lab as a space for experimenting with projects, installations, artworks, resources and ideas connected to the sun. Cyanotype offers a simple example of this approach: sunlight is not only something we observe, but something we can work with directly to make an image.

How to make a cyanotype:

How does it work?
A surface is coated with a light-sensitive iron solution. You then place objects, drawings or a negative on top and expose it to sunlight. The areas that receive light develop into the characteristic deep blue of cyanotype, while the covered areas remain lighter. The blue colour is created through a chemical reaction triggered by light, which produces the pigment known as Prussian blue.

What you’ll need:

• Cyanotype kit (ferric ammonium citrate + potassium ferricyanide)
• Gloves
• Plastic cup
• Sponge
• Surface to print on (eg. watercolour paper or fabric)
• Objects to arrange (leaves, flowers, lace, transparent paper…)
• Glass sheet (optional)
• Sunlight
• Basin of water

Steps:

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide

1️⃣ First, prepare the light-sensitive solution. Put on your gloves and mix equal amounts of the two components from your cyanotype kit in a plastic cup.

Important: Work in a room without direct sunlight while you prepare and apply the solution. Normal indoor lighting is fine.

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide 

2️⃣ Use a sponge to apply the solution evenly to your chosen surface, then leave it to dry completely in the dark. If you prepare more sheets than you need, keep the extras in a light-proof box or folder until you are ready to use them.

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide

3️⃣ Once the surface is dry, you can start creating your image. Arrange leaves, flowers, objects or transparent drawings on top of the coated paper. When you are happy with the composition, carefully take it outside and place it in direct sunlight. If you want clean, sharp outlines, make sure nothing moves during the exposure. You can also experiment with movement and shifting objects if you prefer a less precise result.

Tip: Place a sheet of glass or transparent acrylic over your composition to keep everything flat and in place.

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide

4️⃣ How long the print needs to stay in the sun depends on the weather and the intensity of the light. There is no exact exposure time, so keep an eye on the colour of the paper. Once the coated surface has darkened noticeably, the print is usually ready to be developed.

Tip: A longer exposure generally creates stronger contrast in the finished image.

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide

5️⃣ Remove the objects and rinse the print thoroughly in clean water. Move the paper gently back and forth in the basin and turn it over from time to time. As the remaining solution washes away, the image will become clearer and the blue will begin to deepen.

Excerpt from the Family Day HEK x KHBL Cyanotypie Guide