1/9 pl Thermoplastic Case opened reads "Littlefield, Parsons, & Co., Manufacturers of Daguerreotype Cases.--L., P. & Co., are the sole Proprietors and only legal Manufacturers of UNION CASES with the Embracing Riveted Hinge. Patented October 14, 1856, and April 21, 1857."

Daguerreotype cases were produced with a wood-frame base covered in paper, cloth, or leather, and were molded from plastic. The value of the image case is often considered separately from the value of the image itself, although the cased image is priced as a package. Early image cases were made of wood, and covered with leather, with silk or velvet lining. Samuel Peck is usually credited as having first produced the thermoplastic case, which he called the "union case". Peck used a substance that had been patented by Nelson Goodyear in 1851 as an improvement on India rubber, a compound of sawdust and shellac. Peck never registered his name "union", and so it was used freely by many other manufacturers. Even after the introduction of the union case, production of older style wood-frame cases continued. However, coverings during the late 1850s and early 1860s were usually cardboard and papier-maché, and rarely leather. (Mace 44-46).