Cyanotype Sun Printing: Blueprint Your World in Blue

Master the 19th-century photographic process of cyanotype printing using nothing but sunshine, chemistry, and everyday objects to create striking Prussian blue prints.

Cyanotype is chemistry you can see happen in real time. You coat paper with two iron compounds, arrange objects on top, set it in direct sun, and watch as UV rays turn the exposed areas into that signature Prussian blue. The areas under your objects stay pale. Rinse in water, and the unexposed chemicals wash away, leaving white silhouettes against deep blue—like a photographic negative made without a camera. The magic happens between 10 AM and 2 PM when UV is strongest. On a bright day, you'll see the paper darken from yellow-green to gray-blue in minutes. Leaves show every vein. Feathers capture individual barbs. Lace patterns emerge crisp as laser cuts. You're not just making prints—you're using the same process Anna Atkins used in 1843 to document algae specimens, the same chemistry that gave us architectural blueprints for a century. Start with pre-treated paper if you want immediate results, or mix your own chemistry for pennies per print once you're hooked. Either way, you're working with light-sensitive emulsion that reacts predictably: strong sun, clear contact, thorough rinse. The paper darkens in sun, then lightens dramatically when you rinse it—that moment when the blue blooms deeper is genuinely satisfying every single time.