Salted paper prints exhibit a diverse range of visual characteristics depending on the paper, process variations, and finishing. Examples range from early paper prints by Talbot with a matte paper surface and brown tones to later prints with a semi-shiny surface and cool tones.
Sizing and Toning
Photographers typically used high-quality cotton writing paper for their photographic prints. Nineteenth-century papers were usually produced with gelatin or starch sizing (components added during the manufacturing of the paper). In order to make prints more durable and to achieve distinct visual characteristics, photographers often incorporated other substances into printing papers, a process known as additional sizing. By adding gelatin, starch, resins, or albumen (egg white), photographers could change the surface, create a sharper appearance, or alter the tonality of a print.
An early toning method included the application of heat during the flattening of prints, which made the image appear darker. After 1850, the majority of photographers toned their prints with gold chloride (gold toning) to produce a more desirable cool, purplish-brown color after processing. Conservators today believe that gold toning also resulted in a more stable print. Other toning options included toning with sulfur as well a mixture of gold chloride and sodium thiosulfate, also known as sel d'or toning or toning with platinum.
Salted paper prints were often mounted on a larger piece of paper or board usually with starched-based adhesives. To adhere the print to the mount, photographers sometimes placed prints through a roller and or used a burnisher. These procedures made the surface of the print smoother and achieved a shinier finish. Some photographers never mounted their photographs but kept them in folios in a dark place.
Methods for fixing and washing salt prints were still evolving during the early stages of the process. At this time, photographers observed that many prints were changing color and stains were appearing, even on prints stored away from the light. The application of varnishes and coatings, they learned, provided some protection along with an improved appearance.
A coating also served an aesthetic function as it filled in the tiny areas between the paper fibers on the print surface. In this manner, the naturally matte surface of the salt print took on a rich, saturated appearance creating the optical illusion of a sharper image and a glossier, smoother appearance. Over time, some of these coatings have protected the print, while others have obscured the image with heavy discoloration and cracking.
Retouching and Hand Coloring
The matte surface of the salt print lent itself to hand coloring and retouching. Hand coloring was used to add color, to create a more realistic appearance of the image, and to achieve a more artistic look. Retouching used many of the same tools and techniques as hand coloring, but with the intent of improving the photographic image or covering an imperfection.