Chapter 14
Section 1

Descriptors and Attributes

Nineteenth century photographs share these attributes, individually and in combination:

1. Picture Base:
Brass
Ceramic
Copper
Fabric
Glass
Iron
Ivory
Leather
Paper
Silver-plated copper
Stone
Transparent plastic
Wood

2. Photosensitive Material:
Chromium
Diazo
Iron
Palladium
Platinum
Silver
Uranium

3. Image Type:
Coated-glossy
Coated-matte
Negative
Not coated
Opaque
Positive
Tinted
Toned
Translucent
Transparent

4. Binder:
Albumen
Collodion
Gelatin
Gum arabic
None

5. Mounting:
Case, various materials
Cardboard
Glass
Metal
Some of these characteristics are easy to identify by casual inspection while others require chemical or physical analysis, or close comparison with known standard pictures. In this book there are two levels of examination on which identification can be based:
  1. Visual examination, requiring only adequate light, a pocket scale, and good close vision, possibly aided with a hand magnifier. Observations made in this manner are subjective and the conclusions will always be "possible" rather than "certain".
  2. Analysis, utilizing microscopy and any appropriate laboratory analytical equipment, including both non-destructive and destructive tests, when the need for added confidence justifies the effort