Chapter 6: Provenance – LINGUA FRANCA – A Common Language for Conservators of Photographic Materials

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Chapter 6: Provenance. Image of the interior image of a daguerreotype case, with handwritten text of the names and place where this photograph was taken.


Plate mark

These are stamped marks found on many, but not all daguerreotypes. These stamps are usually located along the exterior edges of the plate, making them invisible when the daguerreotype is sealed with a brass or paper mat. Plate marks usually consist of initials, symbols and sometimes numbers. The number most commonly found is 40, indicating 1 part silver to 39 parts copper, the physical makeup of the plate. These plate marks can also aid in dating the images.

An interesting plate mark was found on a daguerreotype entitled The Carpenter in Canada, taken circa 1850 by an unknown photographer. The plate mark is located in the bottom left corner and includes a six-petal flower as well as the word "DOUBLÉ". Below this is a stamp of a lamb with a cross, known as a "Paschal Lamb". Below this is the name "A.GAUDIN" and the number 40.

Research indicates that the manufacturing company was Alexis Gaudin & Bro., from France. It is unknown when manufacturing began, but the plates were in production until at least 1856. This plate was widely used in North America around 1850 to 1855, with the peak year being 1853. This corresponds to the portrait's estimated date of 1850. The word "DOUBLÉ" in this case means that it is plated silver, rather than dipped, a manufacturing process of daguerreotypes. Once again, the number 40 denotes the portion of silver to copper found in the plate.

A partial image of a man holding a hammer. At the bottom left corner there is a plate mark. A close-up of a daguerreotype plate mark. It depicts a six-petal flower, 'DOUBLÉ', a lamb with a cross, the name 'A.GAUDIN' and the number 40.

Exhibition stamps / labels

Various stamps and stickers on the back can be used to determine when a photograph was on exhibition. They can be used as supportive material to place a photograph in a historical content.

On the back of this item there is a stamp and a sticker. According to the stamp, this item was at the Pittsburgh Salon in March 1922. There is also a sticker that proves the photograph was exhibited at the London Salon of Photography in 1923.

This provides useful information about the history of this photograph. As this photograph was created in 1918, the exhibition stamp and sticker correspond with this date.

Back of a photograph with multiple handwritings, as well as a stamp and a sticker.

Artist signature

Using a catalogue raisonné, a photographer's signature can be traced to other known signatures of the same photographer. This is the signature of John Vanderpant, who had a major influence on Canadian photography in the 1920s and 1930s.

A close-up of an artist's signature.

Stamp on brass mat

A stamp of a name in the brass mat can identify the photographer, if the brass mat has not been previously changed.

Here, the stamp reveals the name T. C. DOANE. Doane was a successful daguerreotypist in Montréal in the 1840s, known for his portraits of prominent Canadians.

A hand coloured photograph of a man and four boys dressed in costume. The photograph is in a case with a brass mat. The bottom left edge has a stamped inscription. A close-up of a photographer's stamp 'T.C. DOANE' on a brass mat.


Inscription are used to identify the sitters, date and place of photographs.

A good example is the portrait of a group of merchants from Yarmouth, Nova Scotia. This handwritten inscription is inside the leather case, hidden from view when the daguerreotype is in the case. It is signed by one of the sitters and lists all the members of the group, as well as the location of the sitting and the name of the daguerreotypist, Wellington Chase.

It reads:

Top Row Wm. Brown. Herman Crowell. Char White. Dave Burton. Lower Row S.M. Ryerson. James Williamson. L.E. Baker. Writing Master Williams O.S. Davison The above are names of those in picture taken by artist Chase in Mason Hall in 1855


Interior image of a daguerreotype case, with handwritten text of the names and place where this photograph was taken.

Paper backprinting

Paper backprinting is an integral part of photographic paper. Paper manufacturers would print their brand names on the back of their photographic paper. They would often change acronyms or underlines or spaces over time. These changes in backprinting have been catalogued and can be used to help identify when the papers were made, but not necessarily when the photographs were actually taken. On the back of the photograph the AGFA symbol is repeated. This particular paper type was available during the 1960s corresponding to the known date of printing, which was1961.

Detailed image of an AGFA stamp on the back of a photograph.
Man leaning on a piano with his elbow, with his head resting on his hand.

Credit: Walter Curtin

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