Tag: Ultra Violet Light

• February 12, 2026

  LIGHT

  Light is the catalytic variable in cyanotype, driving the photochemical reduction of ferric iron (Fe³⁺) to ferrous iron (Fe²⁺). Ultraviolet wavelengths are primarily responsible for initiating this reaction, meaning exposure intensity, spectral quality, and duration directly determine image density and tonal separation. Insufficient UV results in weak, low-contrast prints, while overexposure compresses highlights and reduces…
• February 12, 2026

  SALT

  In cyanotype chemistry, the salt component plays a critical role in image formation and stability. Ferric ammonium citrate and potassium ferricyanide react under UV exposure to form insoluble Prussian blue, but the concentration, purity, and mixing ratios directly affect contrast, density, and tonal range. Small variations in preparation can influence coating consistency, exposure time, and…