or four hours
will sometimes be required.

When the print has become dark enough, it should be removed from the
printing frame and put at once in a dark place where the light cannot
reach it. It is what is known as a proof at this stage, and the light
will turn it black.

About twenty prints can be toned at once, and, as it is a long process,
it is better to wait until several have accumulated than to go through
the various operations with only one or two prints.

They should first be trimmed to the required size. Some amateurs leave
the trimming until after they have finished the toning process, but this
is not advisable for several reasons. In the first place, it is easier
to trim them beforehand, because they lie flat and are not curled up, as
they generally are after toning. None of the toning solution is wasted
in toning the parts that are of no use, and if the accumulated clippings
are saved, they are of some value on account of the silver in them.

The trimming cannot be satisfactorily done with a pair of scissors,
as it is impossible to cut perfectly straight. A thick piece of glass
called a cutting mould is used, and a convenient little instrument
called Robinson's trimmer. If you do not wish to go to the expense of
these articles, however, you can manage very well by using a sharp
pen-knife to cut with and any piece of glass with straight edges to
trim by.

You should have a firm, hard substance to cut on (glass is preferable),
and on this should be put a piece of paper. Upon this paper the print
should be laid face downward, and after you have decided how much of it
you are going to cut away, draw your knife firmly along by the edge of
the glass, pressing down well, and the strips will be cut off leaving a
smooth, straight edge.

After the prints have been trimmed, they should be soaked in water for
fifteen minutes. If you have not running water in which to place them,
the water should be changed several times. This preliminary washing must
be very thorough, or the toning will not be satisfactory.

To prepare your toning bath, make up first a stock solution of fifteen
ounces of water and fifteen grains of chloride of gold and sodium. The
chloride of gold and sodium can be obtained in small bottles which come
for the convenience of the amateur prepared in just the desired
quantity.

For a toning bath for twenty prints, take ten ounces of water, three
grains of sodic bicarbonate, six grains of sodic