Blue Verditer
:
ON THE PRIMARY, BLUE.
or Verditer, is an oxide of copper, formed by precipitating nitrate of
copper with lime. It is of a beautiful light blue colour, little
affected by light, but greened and ultimately blackened by time, damp,
and impure air--changes which ensue even more rapidly in oil than in
water. It is mostly confined to distemper painting and paper-staining.