Patented in 1873 in England, the platinum printing process (sometimes known as platinotypes) enjoyed widespread use between 1880 and 1916. For these prints, a light-sensitive solution of platinum and iron was coated directly onto paper and exposed under a negative. As with salt prints, the sensitized solution saturated the paper fibers, giving the photograph a soft, matte look. Platinum printing practically disappeared during World War I, when an embargo on the metal set prices soaring and made its use for photography unpractical. Many members of Stieglitz’s circle valued platinum prints for their remarkable tonal range and crisp detail.