Skip to Content


5.2 Types of Photographs


POP (printing-out paper): A photographic paper which forms a visible image directly from the reaction of light on light-sensitive materials. POP prints are warm in tone, tending towards a brown, purple, or reddish color. They are almost always made in contact with a negative.

DOP (developing-out paper): A photographic paper which forms a visible image through the use of a chemical developer to reveal the latent image made by exposure to light. DOP prints are cool in color -- blue, neutral, or black -- unless they have been toned. They may be either contact-printed or enlarged from a negative.

Coated paper: A support which has an emulsion layer on its surface consisting of either albumen, gelatin, or collodion. This layer holds the light-sensitive photographic salts. A three layer structure has as its third layer barium sulfate, (aka bryta layer). This layer occurs between the paper and the image layer.

Uncoated paper: A paper support without any emulsion layer. The image often appears to be within the paper.

Distinguishing Characteristics

The following are the most important features used to identify a type of photograph:

  1. Positive or negative
  2. Nature of support material
  3. Texture, surface quality
  4. Color, tone
  5. Characteristics of deterioration

Photoprints (Direct Positives)

Support Materials Technique Date Identifying Features
Silver-plated sheet of copper Daguerreotype 1839 – c. 1860 Mirror surface; positive-negative nature; usually housed in a miniature case made of wood covered with leather, paper, cloth or mother of pearl; and/or made of thermoplastic material.  Tarnish can form on support.
Glass  Ambrotype 1851 – c. 1880 Milky gray highlights; various black backings, occasionally use ruby glass; usually housed in a miniature case.  (See daguerreotype for description.)
Iron, coated with a black varnish ("Japanned surface") containing raw linseed oil, asphaltum and pigments Tintype, ferrotype, melainotype 1854 – c. 1930s Milky gray highlights, lack of contrast in image.  Rust can form.

Photoprints (From a Negative)

Support Materials Technique Date Identifying Features
Uncoated Paper
(1-layer structure)    
Salted paper print 1840 – c. 1860 POP, matte surface; paper fibers visible; often faded to pale yellow, especially at the edges; sometimes varnished.

1880 –
c. 1930
1916 –
c. 1930
Gray-black color, matte surface; paper fibers visible; rich, velvety texture; popular with art photographers; very stable images, no fading or silvering; paper often very acidic and discolored.
c. 1880 – c. 1910
still used
Brilliant blue color, matte surface; invented in 1842 but not used until 1880s; paper fibers visible.
Coated Paper
(2-layer structure)    
Albumen print 1851 – c. 1900s POP, semi-glossy surface; thin paper support, usually on heavy mount; a crackle pattern can often be seen in dark highlights; usually yellowed in highlights; paper fibers visible through albumen coating.
Carbon print 1860 – present Used extensively for reproductions of works of art, also used as tip-ins for books. Subtle image relief; paper fibers visible in highlights; no fading or yellowing; may get large cracks in dark areas; may be any color.
1866 – c. 1900 Same characteristics as carbon prints. Woodburytypes are not photographic, but photomechanical. Mainly used for book illustration and large edition publications; often labeled.
Coated Paper
(3-layer structure)    
Collodion print 1888 – c. 1910
Glossy: late 1880s–1920s
Matte: 1894 – 1920s
POP, glossy surface (sepia, purple color) or matte surface (gold or platinum toned, black color), very stable image, rarely faded; easily abraded; usually mounted; paper fibers not visible. Glossy collodion prints often exhibit a subtle rainbow effect on their surface when viewed under fluorescent lights.
Gelatin POP print (silver chloride) c. 1880 – c. 1910 POP warmer in tonality than a gelatin DOP; usually very glossy; often faded to yellow; paper fibers not visible.
Gelatin DOP print (silver bromide) c. 1880 – present DOP appears black and white unless image deterioration has occurred; matte, glossy or textured; may be toned to various warm shades; often exhibits silvering; may fade; paper fibers not visible.

Photo Negatives

Support Materials Technique Date Identifying Features
Paper   Calotype 1840 – c. 1855 Rare, usually waxed or oiled.
Eastman paper negative 1885 – c. 1895 Rare, usually in poor condition; small format.
Glass   Collodion wet plate 1851 – c. 1880 Plate coated by hand; edges often ground; uneven coating at the edges; varnished.
Gelatin dry plate c. 1880 – c. 1975 Plate is machine coated; cut edges; even coating at edges; occasionally varnished.
Gelatin Eastman American film 1884 – c. 1890 Rare; looks like plastic; brittle, uneven edges; used for Kodak No. 1 (2-1/2" diameter), Kodak No. 2 (3-1/2" diameter)
Plastic     Cellulose nitrate(sheet film) 1913 – 1939 "NITRATE" marked on edge; very flammable; small clipping sinks in trichloroethylene; degraded products smell very acrid; becomes yellow, brittle, sticky.
Cellulose acetate,diacetate, triacetate, etc. 1925 – present "SAFETY" marked on edge; burns with difficulty; clipping floats in trichloroethylene; degraded products smell of acetic acid (vinegar); channels form between base and emulsion as the negative deteriorates.
Polyester c. 1965 – present When viewed between polarizing filters, the film is identified by interference patterns (rainbow colors);1 may include edge printing "SAFETY."  
  1. See preservation leaflet “A Short Guide to Film Base Photographic Materials:  Identification, Care, and Duplication.”


Written by Gary Albright and Monique Fischer


Creative Commons License image