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Printed-out silver chloride paper was typically glossy;
a matt fi nish could be produced by squeegeeing the print
face down on a sheet of ground glass and allowing it to
dry in situ. This was common practice; platinotype and
bromide papers had encouraged a preference for matt
prints. In the early 1890s, matt developing-out papers
were manufactured with rice starch and resin (shellac).
In addition, the baryta substrate could be embossed to
provide a textured fi nish. Chlorobromide paper usually
had a matt and/or textured surface fi nish.
Printing-out papers show a warm brown colour (un-
less toned), because printed-out silver is deposited as
small, spherical particles of metallic silver, which absorb
blue light and refl ect yellow light. Since brown is really
a dark yellow, light refl ected from spherical particles
is perceived by the human eye as having a brown hue.
‘POP’ papers were usually gold-toned, giving a colder,
purple-brown colour, and many ‘self-toning’ papers
were manufactured with integral gold chloride. This was
further moderated by a tinted blue-grey or lavender-grey
baryta substrate, which suited the primary application
of POP for commercial portraiture. The paper was also
used for proofi ng negatives and printing early snapshot
photographs.
Developing-out paper tends to a neutral-black image
colour (unless toned), because developed-out silver is
deposited as a tangle of fi lamentary silver whose light
absorbing properties produce the appearance of a neu-
tral-black hue. But platinum and bromide papers had
established the taste for a colder image colour, which
manufacturers produced in gaslight papers by modify-
ing emulsion chemistry and developers. Gaslight paper
responded well to a variety of developers; gallic acid
gave a greenish-black to brown image colour, while
hydroquinone and ammonium carbonate created a
warm red. Additionally, decreasing the exposure time
and increasing development affected the grain structure
of the silver and shifted the hue towards black. Chlo-
robromide produced a warm-neutral black, but could
be developed for brown tones, which were emphasized
by an ivory or cream tinted paper base. These attributes
suited portrait work, for which chlorobromide papers
were typically used.
In the 1850s, platinic chloride was proposed forGELATINE SILVER PRINT
Unknown, Unknown School. Large
Shrine Figure in Happy Valley,
Gwalior, India.
The Metropolitan Museum of Art,
Purchase, Cynthia Hazen Polsky
Gift, 1993 (1993.126) Image © The
Metropolitan Museum of Art.