Plumb Bob
Plumb Bob
Plumb Bob

Sean Kernan

Plumb Bob

1995

Original Gelatin Silver Photograph

Image dimensions: 17" x 14"
Mounted dimensions: 24" x 20"

Pristine condition

certified authentic
Add to Collection — $1,300
Plumb Bob
Plumb Bob
Plumb Bob

Details

Description

Gelatin Silver photograph by Sean Kernan, "Plumb Bob." Individually handmade by Kernan from 4x5 Type 55 Polaroid film with fiber-based photographic paper. Signed and numbered in an edition of 18 in ink along lower edge. Corner-mounted on 20x24 inch cotton rag museum board.

Condition

The HD Video of the actual work in question has been provided as a visual condition report. If you would like a written condition report in addition to the HD video, please

Medium

Polaroid Type 55 film is a black-and-white peel-apart 4×5 format Polaroid film that yields both a positive and a negative that can be used to create enlargements. The film speed is 50 ISO for the positive and 25 ISO for the negative. A self-contained waterproof transparent sleeve containing positive and negative film sheets and a small reservoir of reagent gel is inserted into the film holder, Packet Back, and once the exposure is made and the holder is removed. By flipping a lever and withdrawing the sleeve the gel is squeezed between the negative and positive emulsion layers. After the set time the layers can be peeled apart, some gel is retained at the edges, creating positive and negative images.

type 55 polaroid film

The most popular black and white process of the 20th century was gelatin silver, in which the image consists of silver metal particles suspended in a gelatin layer. Gelatin silver papers are commercially manufactured by applying an emulsion of light-sensitive silver salts in gelatin to a sheet of paper coated with a layer of baryta, a white pigment mixed with gelatin. The sensitized paper, generally fiber-based, is exposed to light through a negative and then made visible in a chemical reducing solution. William Henry Fox Talbot introduced the basic chemical process in 1839, but the more complex gelatin silver process did not become the most common method of black-and-white darkroom photography until the late 1910s. Because the silver image is suspended in a gelatin emulsion that rests on a pigment-coated paper, gelatin silver can be sharply defined and highly detailed in comparison to platinum or palladium, in which the image is absorbed directly into the fibers of the paper.

Cross section of Gelatin Silver paper