Mad Hatters and the Anatomy of a Daguerreotype

Did you know that October is American Archives Month? To celebrate, we’ll be sharing some behind-the-scenes stories from our Photograph Collection and highlighting some of the work we do to preserve, organize, describe and provide access to the images in our collection. This summer our staff, interns and volunteers have been been digitizing, researching and cataloging our Early Photography collection: 600 daguerreotypes, ambrotypes and tintypes. 

Black-and-white image of Emily Moazami, Photo Archivist & Associate Curator of Photography at History Colorado

Emily Moazami, Photo Archivist & Associate Curator of Photography at History Colorado

So what exactly are these photos? Let’s start with the earliest: the daguerreotype.

The daguerreotype, named after inventor Louis-Jacques-Mandé Daguerre, was the first mass-produced photo process in the world and was most commonly created between 1840 to 1865. It was made of a polished copper plate coated with light-sensitive silver salts. When the photographer placed this plate in a camera and exposed it to light, an image was created directly on the plate, a process known as a direct positive. Because the image is fixed directly on the plate, there is no negative and it is usually laterally reversed (a mirror image)  unless the photographer used a prism to correct this. Daguerreotypes are easy to identify because they reflect like a mirror when held at certain angles.

Daguerreotype of Charles Jermone (1815-1873) taken by an unidentified photographer circa 1847-1851

Daguerreotype of Charles Jermone (1815-1873) taken by an unidentified photographer circa 1847-1851 (10051606a)

Creating daguerreotypes was very technical and involved a number of dangerous chemicals including mercury, cyanide and sulfuric acid. There were even reports of some photographers getting “mad-hatter syndrome,” or mercury poisoning. Despite this, it’s estimated that 30 million daguerreotypes were created in the United States and it’s believed that the daguerreotype photo process made its way to Colorado in 1853.

Blank copper plates, used in the process of making daguerreotypes, in a wooden storage container

A case holding blank copper plates.

Daguerreotype being held by a rubber-gloved hand

Daguerreotypes reflect like a mirror when held at certain angles

So here’s a challenge for you: Sit completely still for 5 minutes with your eyes focused on one fixed point and try to look pleasant. If you did this test correctly, then you probably failed miserably. This was the dilemma that early daguerreotypists faced. Exposure times were anywhere from 5 to 70 minutes! Therefore, the subject matter of the very earliest daguerreotypes was limited to things like a bowl of apples or architecture. However, by 1840 technological advancements in camera lenses, along with altered chemistry, allowed for a quicker exposure time and the first photographic portraits. Even with these improvements, though, the exposure times were still fairly long compared to modern standards. In 1843 it still took between 5 and 60 seconds to capture an image in moderate light. Due to these long exposure times, sitters were often propped against metal head rests and instructed not to smile. Any movement could render the final image blurry or result in two noses, three chins and one eye.

Daguerreotypes offered a cheaper alternative to painting portraiture to capture one’s likeness, but they were still expensive to create, so they largely depict the most affluent people in a region who could afford a studio session. When sitting for a daguerreotype, people almost always wore their very best clothes for the special occasion; the photographer often hand-colored the final image with pigments to make the portrait more lifelike by adding, say, a blush of color to the cheeks or gold pigment to the sitter’s jewelry.

Four ceramic palettes used for mixing pigments

Ceramic palettes used for mixing pigments

Let’s take a closer look at the anatomy of a cased daguerreotype:

  1. The case, which holds all the elements together, was often made of wood with a thin layer of leather on top. Or, a thermoplastic case, also known as a union case, was made of pressed sawdust and gum shellac. The backside of cases often featured decorative motifs, which became more elaborate over time. Daguerreotypes were sometimes housed in other formats, such as pins or lockets.
  2. The felt or silk cushion lining the case on the opposite side of the image was designed to protect the glass from getting scratched or broken.
  3. The daguerreotype itself was placed opposite the felt cushion.
  4. The mat, laid over the daguerreotype, came in a variety of shapes, sizes and textures, but was most commonly made of brass. It was designed to hide imperfections, such as the photographer’s fingerprints around the daguerreotype edges.
  5. A piece of glass was placed over the daguerreotype and mat to protect the surface of the image from getting scratched or damaged.
  6. The preserver is a piece of brass that was often decorated with ornate designs. Daguerreotypes can oxidize and tarnish if they’re exposed to the air, which will eventually leave stains on the image. To help prevent this, the edges of the daguerreotype, glass and mat were taped together and the preserver was then wrapped around them to help prevent air from leaking in. Preservers were not used prior to 1847.
Photograph of a girl used to diagram the anatomy of a daguerreotype as outlined in the text

Anatomy of a Daguerreotype

By 1865 the daguerreotype fell out of favor for cheaper photo processes like the ambrotype and tintype. But the daguerreotype isn’t dead! There are still fine art photographers who work in the medium and workshops offered all over the world to help keep this photo process alive.

Want to see some of the daguerreotypes we’ve cataloged? Head over to our collection online at  and search for the term “daguerreotype.” While you’re there, click Highlights (second tab) and select the “Early Photography” category to see all the photos from this collection that we’ve cataloged so far!

Stay tuned for descriptions of ambrotypes, tintypes and the hidden surprise we found in our collections, the opalotype!