Development is effected by
sliding the print face downward on to the developer, which must be
rocked after the development of each print to avoid scum marks. To
clear the prints they are washed in three or four baths of a weak
solution of hydrochloric acid after leaving the developer, to remove
all traces of the iron salts, and finally washed for a quarter of an
hour in three changes of water; they are then finished, and may be
dried between clean blotting paper.
Pizzighelli's process differs from the above in being one that prints
fully out in the frame without development; the paper contains the
platinum and iron salts as well as the developer, and so prints and
develops at the same time. Although excellent prints can be produced
with it, for general work the results of the paper, as at present
made, will not compare with the hot and cold bath processes. It is,
however, excellent for printing from very dense negatives, and
occasional negatives that seem extremely suitable for it. The paper
should be breathed on before printing, as if it is quite dry the
printing will be very slow and irregular. The best conditions for the
preparation of the paper have scarcely been decided upon yet, and it
is not quite fair to judge the process. The prints are cleared in the
acid baths and washed for about a quarter of an hour.
The sepia and black hot bath processes are much alike in the general
treatment.
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