Helmut Gernsheim & Alison Gernsheim, The History of Photography: From the Camera Obscura to the Beginning of the Modern Era

30 Photography on film
For a long time photographers had been desirous of replacing glass plates by a less
heavy and fragile support, but it proved extremely difficult to find a material as
transparent and smooth as glass, as light as paper, yet free from its impurities and
grain. Before the ideal support for emulsion-celluloid-was manufactured in an even
and thin quality suitable for photographic purposes, photography on film took two
distinct forms-stripping film and flexible film, while simultaneously there was a
short-lived revival of paper negatives.
STRIPPING FILM
Stripping film was a paper negative, with this difference: the paper was merely
employed as a support for the emulsion, which was peeled off before printing, to
avoid the grain of the paper being reproduced in the positive.
The advantage of stripping the sensitive layer from its support had first occurred
to SCOTT ARCHER, who mentioned stripping by means of a solution of gutta-percha
in his communication of the collodion process in March 18 5 1. After improvements
to facilitate the removal of the collodion layer, he patented the method in August
1855. It consisted in coating the finished and varnished negative with several layers
of transparent gutta-percha. On immersion in water, the collodion separated from
the glass, and Archer obtained 'tough and flexible photographic pictures capable of
being used for the production of positive pictures'. The purpose of stripping was to
reduce the weight of glass plates when on a long photographic tour, for, after stripping,
the film could be kept in a portfolio and the plates used again. This did not, of
course, help in ordinary day-to-day photography, and neither Archer's procedure
nor that put forward a few months later by the REV. J. B. READE, using gutta-percha
as a substratum, found much favour. The same applies to the method patented by
ALEXANDER PARKES in May 1856, with a substratum of plain collodion, and J. A.
FERRIER ' s method (patented in September 1857) by which a sensitive surface was
formed on plain collodion which had been spread on a smooth surface of gelatine,
gutta-percha, starch, or similar material and coated with albumen and sensitized.
After washing and drying, this compound film was attached to a glass plate to
facilitate exposure and processing. Afterwards, a solution of gelatine was poured over
the negative and when dry, the top three layers were detached from the smooth
gelatine or gutta-percha surface which remained on the glass. The albumen picture
was thus sandwiched between a layer of collodion on one side and a layer of gelatine
on the other. Stripping positive images on collodion, however, had two important