yes - but as with most replacements there is a residual chemical remnant, hence the iron sulfinate. It’s the remnant chemical stain that they solualized in the base hydroxyl solution.
Given the chemical composition of squid ink, do you see the problem with your fossilization argument, FormerR?
Cephalopod (squid) ink contains a number of chemicals in a variety of different concentrations, depending on the species. However, its main constituents are melanin and mucus. It can also contain, among other things, tyrosinase, dopamine and L-DOPA,[5] and small amounts of amino acids, including taurine, aspartic acid, glutamic acid, alanine and lysine.[4]
I did not notice that as an ingredient in squid ink (melanin was the major component). However, chemistry is not my strong suit.