Forest black is a permanent dark green ink that darkens further as it dries. This ink is waterproof, lightfast, flows well, and dries well.
Platinum Forest Black is a modern iron gall ink, which means it’s permanent (and becomes even more permanent as it darkens with time). If you leave this to dry in cheap steel nibs, it may corrode them (iron gall inks are acidic), but it’s perfectly safe for normal use.
Forest black is a permanent dark green ink that darkens further as it dries. This ink is waterproof, lightfast, flows well, and dries well.
Platinum Forest Black is a modern iron gall ink, which means it’s permanent (and becomes even more permanent as it darkens with time). If you leave this to dry in cheap steel nibs, it may corrode them (iron gall inks are acidic), but it’s perfectly safe for normal use.