By the middle of the 19th century, photography was becoming affordable to the average American. In its earliest forms known as ambrotypes and dagguerotypes, images were captured on glass plates. The results were fragile and lacked contrast.
In 1853, a Frenchman named Alexandre Martin introduced the tintype process by placing a sensitized collodion emulsion on a metallic sheet that resulted in a direct positive image which was both fast and inexpensive to produce. It also yielded much higher quality photographs, which were sold in various sizes, the most common of which was known as the 1/6th plate, and was 2 ¾” X 3 ¼”. The positive image was a one-of-a-kind with no duplication process involved. Innovative photographers retouched the emulsions, adding rose to the subject’s cheeks, color to their trousers or uniforms, and gilt to their buttons, buckles or headgear insignia.
Most such plates were held in a leather or thermoplastic carrying case under protective glass, fastened in place behind a brass matte. Now, the Civil War soldier could carry an image of his loved ones into the field. In turn camp photographers produced many images that the soldiers sent home to family.