Ferric ammonium citrate and potassium ferricyanide. This bottle contains the ferricyanide half of that equation, the chemical that transforms your light-exposed surface into that distinctive Prussian blue print. Mix equal parts of both solutions, brush onto paper or fabric, let dry in darkness, then expose with objects or photographic negatives to create permanent cyan images.

The process itself feels magical: watch areas blocked from UV light remain white while exposed sections develop into deep blue during water rinse. Natural objects like leaves and feathers produce crisp contact prints with every vein and edge preserved. Digital negatives printed on transparency film yield photographs with remarkable tonal range and fine detail. Jacquard's potassium ferricyanide maintains consistent strength for predictable results across multiple printing sessions.

This chemical suits serious alternative process photographers exploring historical techniques alongside mixed media artists layering cyanotypes into collage work. Fabric artists achieve washfast prints on natural fibers for quilting and textile art. The nontoxic formula makes cyanotype accessible for classroom demonstrations and family projects, though you'll still want proper ventilation and skin protection during mixing and application.