The equipment necessary for systematic tinting and toning is
essentially the same as that required for development, consisting of
the usual tanks and racks or small drums, only it is advisable that
they should be used for this purpose exclusively and, if possible,
occupy a separate room to exclude any possibility of contaminating
the developing solutions by the copper or sulphiding bath, which
would cause development fog immediately.
The “drum” system, on account of the expense involved in apparatus
and the larger space required for manipulation, is not to be
recommended for tinting and toning operations, though for operation
on a small scale, a small wooden drum revolving in a shallow wooden
tank is most efficient and economical.
When the tank and rack system is employed, the tanks should be of
slate or other resistive material, and have an outlet at the bottom
in the form of a hard-rubber stopcock or a plain wooden plug. The
racks or drums may be of wood, but if metal pegs are employed on
the racks they should be coated with acid-resisting paint such as
asphalt, since the presence of any metallic surface in the toning
baths will cause contamination and effect a precipitation of sludge.
The frames should not be interchanged but kept separate either for
tinting or toning to prevent contamination of one bath with racks
previously employed in another. This also applies to the small drum
system. For instance, a pink tint would be ruined by using a rack
which had previously been immersed in a deep blue dye-bath, unless
that particular rack had been thoroughly washed. In the case of
delicate tinting, however, no harm is done providing the racks have
been previously coated with the following waterproof varnish: