The art of cyanotype: how sunlight builds deep blue memory

Cyanotype is one of the oldest photographic printing processes. Sir John Herschel discovered the light-sensitive properties of iron salts in 1842 and named the resulting Prussian-blue images cyanotypes. Within a decade, Anna Atkins had used the technique to produce the first photographically illustrated book, a study of British seaweeds. Architects later adopted the same chemistry for technical drawings, and that practical descendant is what most people still call a blueprint.

Almost two centuries later, the recipe is barely changed. No darkroom, no enlarger, no exotic chemicals: just a pair of iron salts, paper, glass, and a few hours of direct sun. That handmade simplicity is why contemporary photographers, printmakers, and textile artists have rediscovered the medium.

Few countries are better placed to indulge in it than Australia. Sydney averages more than seven hours of bright sunshine a day through summer, Perth tops the national charts for clear-sky hours, and even Hobart delivers crisp, unfiltered rays in its milder seasons. The country's famously high UV index, usually discussed alongside Cancer Council warnings, gives Australian printers a near-perfect natural exposure source.

A brief history of sun prints

Herschel announced his findings before the Royal Society, and the technique quickly spread among botanists and engineers. Anna Atkins made thousands of contact prints between 1843 and her death in 1871, placing specimens directly on sensitised paper and letting the sun do the rest. Her study of algae and ferns is now a landmark in both photography and scientific illustration.

By the 1880s, cyanotype had migrated into the drafting room. Architects valued it because the Prussian-blue lines reproduced beautifully and resisted smudging. For about a century, blueprint meant a working drawing rather than a fine-art print, and the artistic side of the medium faded quietly into the background.

The chemistry behind the blue

The working solution depends on just two ingredients. Ferric ammonium citrate and potassium ferricyanide are dissolved separately, mixed in equal parts, and brushed onto paper, cotton, or silk. Once dry, the coated surface is photosensitive: any area hit by strong ultraviolet light hardens, while the parts kept in shadow wash away in a simple water bath.

What remains is pure Prussian blue. Most Australian printers leave the colour untouched, though it can be coaxed warmer with a dilute peroxide rinse. There is something reassuring about a process whose only variables are sun, shade, and patience, particularly in an era when so much photography happens invisibly, inside screens.

Australian light and the perfect conditions

Exposure times vary with season and latitude. In Brisbane on a midsummer noon, a sensitised sheet may be ready in under three minutes. In Melbourne during a winter morning, the same print can need thirty minutes under glass. The Cancer Council's daily UV alert is a handy exposure guide, and many printers glance at the Bureau of Meteorology forecast before setting up.

Tasmania's east coast and the south-west of Western Australia are especially prized for the soft, even glow of their late afternoons. The same harsh light that prompts Slip Slop Slap advice is exactly what iron-coated paper is waiting for.

Bush botanicals and local inspiration

Australian subject matter gives the process its own vocabulary. Pressed eucalyptus leaves throw intricate shadowgrams, banksia flowers leave lacy silhouettes, and she-oak needles produce almost photographic textures. Contemporary printers often collaborate with native plant nurseries in Adelaide and Fremantle to source ethically gathered specimens for their compositions.

A single wattle sprig on sensitised cotton can become a wearable scarf or a stretched canvas. Some artists layer several exposures into montages combining local flora with lace, feathers, or wire mesh, and prints such as Milos's botanical series show just how varied those montages can be. The negative shapes left behind in deep blue are as evocative as the positive prints themselves.

Fabric, architecture, and mixed media

The same sensitiser can be brushed onto silk, linen, or pre-washed cotton, and the cloth holds colour through years of gentle washing. Designers in Melbourne's fashion scene have released capsule collections featuring cyanotype-printed scarves, each one a contact print made directly in the sun. The technique also suits architectural studies: heavy watercolour paper pressed against a brick wall or an ornate balustrade captures detail that digital photography often flattens.

Mixed-media artists frequently combine cyanotype with stitching, embroidery, or gouache highlights. The blue becomes a background for figurative work, a mood rather than a subject. That flexibility is why workshops are appearing in community centres from Parramatta to Port Adelaide, with beginners producing finished pieces in a single afternoon.

Building a creative community

Sharing finished prints has always been part of the tradition, going back to the loose-leaf albums Atkins circulated among her peers. Today, photographers and printers gather at markets such as Paddington in Sydney, Salamanca Place in Hobart, and the Mindil Beach sunset markets in Darwin, where visitors watch prints develop in real time and take a freshly rinsed sheet home.

Online, the conversation has moved well beyond dusty forums. A member gallery on Things We Like collects thousands of blue-toned prints from around the country, and the comments under each upload often include detailed notes on exposure times, water hardness, and which Australian native species print most cleanly.

Practical tips for first-time printers

Working with cyanotype is forgiving, but a few small habits separate a flat print from a richly toned one.

• Mix the sensitiser in low light and store it in an opaque bottle for no more than a week.
• Brush the solution on in even horizontal strokes, then dry it in a darkened cupboard.
• Place your object on the coated surface and weight it with clean glass to keep contact tight.
• Expose until coated areas turn a pale bronze-green rather than bright yellow.
• Rinse in clean cool water until the runoff runs clear, then air dry out of direct sun.

The deep Prussian blue of a finished cyanotype tends to darken slightly in the first twenty-four hours, so it is worth waiting before deciding whether a print needs another session in the sun.

The next step is letting other people see what you have made. Upload your finished prints, in-progress contact frames, and even your beautifully failed experiments to the community feed. Tag your images with the local flora or the suburb where they were exposed, and watch the conversation grow. Whether you print on paper, silk, or a stretched cotton tote, the sun is already waiting, and the archive at Things We Like is ready to hold your work.