Page 117 - The Wellington photographic handbook

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reduced in intensity. The negative is then placed in a clean fixing
bath for an hour or so, when most of the stains will entirely disappear.
Thorough washing is, of course, necessary to complete the operation.
When a fair number of prints are ready they can be toned or,
if self-toning paper is used, finished as described later. Whatever
the kind of WELLINGTON P.O. P. employed, it should be
remembered that to secure the best results the prints should be
finished the same day as printed. Moreover, prints are never so
good if the printing itself is begun on one day and finished on
the next.
TONING P.O.P.
Before toning the prints must be washed in several changes of
water, or better still, in running water. This need not take more
than a quarter of an hour, but it is important, if the toning is to
be easy and regular, that it should be done thoroughly. In this,
as in other processes, it is not sufficient to leave a number of prints
in water lying on the top of one another ; they must be separated,
and separately drained when transferring from one bath to another.
After the washing the prints must be placed quickly, one at a time,
in the following toning bath :
THE SULPHOCYANIDE TONING BATH.*
Ammonium Sulphocyanide ... 20 grains 3 grammes
Gold Chloride 2 „ 30 c.c. (1% sol.)
Water to ... ... ... 16 ounces. 1 litre.
An excess of the sulphocyanide beyond the quantity given should
be avoided, or pink high-lights and half-tones, and the defect
known as double toning, i.e., red shadows and bluish high-lights
may result. The sulphocyanide must be dissolved in the water
first, and then the gold, previously dissolved in water, added. A
deep red colour will be seen for a moment, and as soon as the solution
is free from this it is ready for use. Sixteen ounces (450 c.c.) are
sufficient for twenty-four half-plate prints. (For instruction
regarding the preparation of the gold chloride solution, see
page 128).
It is most important that the prints be kept moving while
in this solution. They should be turned over and over, the bottom
* Before making up any formula, read the notes on -pages 125, 126 and 134.
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