Image Image Image 01 Image Image Image Image Image Image Image Image Image Image
Sunlight Art Gallery EnglishSunlight Art Gallery
Your cart
Total: 0
Proceed
You pay immediately upon receipt.
You get all instructions on email about how to pay using bank account.
Name:

Phone:

Email:
Payment Type:





Thank you!
Scroll to Top

To top

Gelatin silver print

Gelatin silver prints were the dominant photographic process nearly from the period of their introduction in the 1880s until the 1960s when they were eclipsed by consumer color photography. As such, the gelatin silver or black-and-white print represents a primary form of visual documentation in the 20th century. Their widespread use in applications as wide-ranging as fine art, snap shots, and document reproduction led to an extraordinary variety of papers, with a wide range of available surface texture and gloss, and paper thickness.

Gelatin silver print paper was being made as early as 1874 on a commercial basis, but was of poor quality, being a dry plate emulsion that was coated onto paper only as an afterthought. Coating machines for the production of continuous rolls of sensitized paper were in use by the mid-1880s, though widespread adoption of gelatin silver print materials did not occur until the 1890s. The earliest papers had no baryta layer, and it was not until the 1890s that baryta coating became a commercial operation, first in Germany, in 1894, and then taken up by Kodak by 1900. Although the baryta layer plays an important part in the manufacture of smooth and glossy prints, the baryta paper of the 1890s did not produce the lustrous or glossy print surface that became the standard for fine art photography in the twentieth century. Matting agents, textured papers, and thin baryta layers that were not heavily calendered produced a low-gloss and textured appearance. The higher gloss papers first became popular in the 1920s and 30s as photography transitioned from pictorialism into modernism, photojournalism, and “straight” photography.

Timeline

  • 1874 First commercial production of gelatin developing out paper (DOP)
  • 1885 Coating machines first used in gelatin DOP manufacture for manufacture of continuous rolls
  • 1894 Baryta layer added to commercial gelatin DOP manufacture
  • 1920s Increasing popularity of glossy and semi-gloss papers
  • 1960s Color photography eclipses black and white for the first time

Technology

Overview

The gelatin silver print or gelatin developing out paper (DOP) is a monochrome imaging process based on the light sensitivity of silver halides. They have been made for both contact printing and enlarging purposes by modifying the paper’s light sensitivity. A brief exposure to a negative produces a latent image, which is then made visible by a developing agent. The image is then made permanent by treatment in a photographic fixer, which removes the remaining light sensitive silver halides. And finally, a water bath clears the fixer from the print. The final image consists of small particles of silver bound in a layer of gelatin. This gelatin image layer is only one of the four layers found in a typical gelatin silver print, which typically include the overcoat, image layer, baryta, and paper support.

Layer structure

A gelatin silver print is composed of four layers: paper base, baryta, gelatin binder, and a protective gelatin layer or overcoat. The multi-layer structure of the gelatin silver print and the sensitivity of the silver imaging salts require specialized coating equipment and fastidious manufacturing technique to produce a consistent product that is free of impurities harmful to the image. The paper base or support serves as the substrate onto which the subsequent layers are attached. Paper is in many ways an ideal support: it is lightweight, flexible, and strong enough to withstand both wet processing and regular handling. The photographic paper base must be free of photoactive impurities such as iron and lignins. In order to obtain this purity, the paper was originally made from cotton rags, though after World War I there was a transition to purified wood pulp, which has been used ever since. The second layer is the baryta, a white opaque coating made primarily from gelatin and barium sulfate. Its purpose is to cover the paper fibers and form a smooth surface upon which to coat the gelatin. Surface textures are created by a variety of textured felts used in the drying of the paper, calendaring, and embossing before or after application of the baryta layer depending on the desired effect. The third layer is the gelatin binder that holds the silver grains of the photographic image. Gelatin has many qualities that make it an ideal photographic binder. Among these are toughness and abrasion resistance when dry and its ability to swell and allow the penetration of processing solutions. The fourth layer, called the overcoat, supercoat, or topcoat, is a very thin layer of hardened gelatin that is applied on top of the gelatin binder. It acts as a protective layer, providing superior abrasion resistance to the print surface.

Image/Processing

Before a paper is exposed, the image layer is a clear gelatin matrix holding the light-sensitive silver halides. For gelatin silver prints, these silver halides are typically combinations of silver bromide and silver chloride. Exposure to a negative is typically done with an enlarger, although contact printing was also popular, particularly among amateurs in the early twentieth century and among users of large format cameras. Wherever the light strikes the paper the silver halides form small specks of silver metal on their surface. Light causes a reduction of the silver salt to silver metal. This exposure is the greatest in areas of the print corresponding to clear parts of the negatives, which become the shadows or high density areas of the print. This process is the formation of the latent image, as it forms an invisible image in the paper that is subsequently made visible by development. So the paper is now placed in the developer, which transforms the silver halide particles that have a latent image speck on them into metallic silver. Now the image is visible, but the remaining unexposed silver halide must still be removed to make the image permanent. But first the print is placed into the stop bath, which stops development and prevents the developer from contaminating the next bath: the fixer. The fixer, typically sodium thiosulfate, is able to remove the unexposed silver halide by forming a water soluble complex with it. And finally, a water wash sometimes preceded by a washing aid removes the fixer from the print, leaving an image composed of silver particles held in the clear gelatin image layer. Toning is sometimes used for permanence or aesthetic purposes and follows the fixing step. Selenium, gold, and sulfur toners are the most common and act by either partially converting the silver to another compound (such as silver selenide or silver sulfide) or partially replacing the silver with another metal (such as gold).