Glass plate negatives use two formats: collodion wet plate negatives and gelatin dry plate negatives. Both formats have a light-sensitive emulsion with a binder layered onto one side of a glass plate. Glass plate negatives were widely used, and we have many images made with glass negatives in our collection. Click here to view all of our glass plate images.
Origins of Glass Plate Negatives
The first photographic negatives used glass plates as a base. They were in use from the 1850s-the 1920s and were popular with amateur and professional photographers alike. Using glass, rather than paper, as a foundation allowed for sharper, more stable, and more detailed negatives. It also allowed multiple prints to be produced from one negative.
Collodion Wet Plate
Frederick Scoff Archer is credited with inventing wet plate negatives in 1851, and they were in use until the 1880s. Wet plate negatives commonly have uneven emulsion coatings, and are made using thick glass with rough edges. A quirk of the wet plate process is that the photographers' thumbprint is often visible on the edge of the glass plate from holding it while applying the collodion emulsion coating.
Not a Portable Process
The wet plate process was not easy to take out into the field. The entire process, from exposure to processing, had to happen before the emulsion on the plate dried, which typically took about five minutes.
A darkroom (a room completely devoid of light) was required to develop the images. Photographers using the wet plate process needed to either stay close to their darkrooms or recreate a portable darkroom to take with them into the field
Gelatin Dry Plate
Dr. Richard L. Maddox invented the dry plate method, which first became available in 1873. Dry plate negatives became the first economically successful durable photographic method. The main advantages of dry plate negatives were that they were typically on thinner glass plates, making them lighter, and they had a more evenly coated emulsion. These improvements were so significant that the dry plate process entirely replaced the wet plate process. Within ten years dry plates were being mass-produced and were widely available to photographers; they continued to be commonly used into the 1920s.
Greater Portability
As the name suggests, dry plate negatives were usable when dry, so photographers could prepare their negatives in advance and develop them well after initial exposure. This gave photographers greater mobility and convenience, allowing them to make photographs far from their darkrooms without worry of developing times. While dry plates allowed for much greater portability, they were still fragile and heavy, needing to be handled carefully.
