First developed in the United States by Hamilton L. Smith, the Tintype process sought to both reduce the cost and increase the durability of the Ambrotype by using varnished sheets of tin in place of original glass. This now meant that a direct positive image could be obtained without requiring a protective case (even though some early melainotypes and tintypes were displayed in cases in accordance with contemporary fashion) or the application of an opaque backing.
Titnypes are similar in contrast and image quality to ambrotypes, and later uncased specimens can easily be identified by the thin, flexible metal to which the emulsion is applied. Often the flexibility of the plates can cause fine cracking in the hardened emulsion over the image surface, providing a tell-tale indicator of the process. Additionally, a magnet may be used to identify that the image is on a ferrous metal plate and not glass or a silver-clad copper plate.