Page 116 - The Wellington photographic handbook

WELLINGTON P.O. P. is so packed as to remain in good
condition for many months. If a packet is opened, and all is not
used, the remaining pieces should be wrapped up as before, replaced
in the envelope, and put aside, preferably under a book or weight.
It is best kept in a cool place, and should on no account be stored
where gas fumes or the fumes from the sodium sulphide used
for toning bromide paper, can gain access to it. It is well to re-
member that while the air in a room may seem quite pure, that near
the ceiling may be both hot and foul, and a high shelf is therefore
always a very bad place on which to keep P.O. P., or for that matter
any other sensitive material. A slight discoloration caused by
improper keeping may disappear in the processes of toning and
fixing, but if it is strongly marked the paper is spoilt.
Printing is best carried out in as bright a light as possible,
short of direct sunlight, which is always to be avoided. If the
negatives are very thin, a piece of green glass, or if that is not
available, green or white tissue paper, placed over the frame, will
enable a more vigorous print to be obtained.
The depth to which printing should be carried is easily learnt.
There is a certain amount of falling off in the processes of toning
and fixing which must be allowed for, but this is not very great.
The prints when taken from the frame must, therefore, look a little
darker than it is desired that they shall be when finished.
If the paper or the negative is damp, or if either become damp
during printing, the silver salts in the paper will affect the negative
giving rise to dark spots called silver stains. If these spots are
not very intense they can sometimes be removed by placing the
negative for an hour or two in the combined toning and fixing bath,
to be described later on. The negative must then be thoroughly
washed and dried.
Another method of removing silver stains is to rub the negative
lightly with metal polish (" Globe," or one of the liquid polishes
is suitable), applying with a tuft of cotton wool and polishing off
with a clean piece. The surface of the negative will now look
almost as shiny as glass, and the stains will have been greatly
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