Frankfort Black
:
ON THE NEUTRAL, BLACK.
is said to be made of the lees of wine from which the tartar has been
washed, by burning, in the manner of ivory black; although the inferior
sort is merely the levigated charcoal of woods, of which the hardest,
such as box and ebony, yield the best. Fine Frankfort black, though
almost confined to copper-plate printing, is one of the best black
pigments extant, being of a neutral colour, next in intensity to lamp
black, and more powerful than that of ivory. Strong light has the effect
of deepening its colour. It is probable that this was the black used by
some of the Flemish painters, and that the pureness of the greys formed
therewith is due to the property of charred substances of preventing
discolourment.