Bookbinding and Remove Foxing:
The fungal spore is attracted to and accelerated by the (F)errous (Ox)ide, (iron), one of the chemicals in the paper...This of course is where it gets it's name, absolutely nothing to do with Reynard whatsoever.
Period Fine Bindings have developed a safe aqueous formulae which neutralises the spore and removes the stain completely without altering the integrity of the fibres of the paper or the medium ....be it ink or water colour etc...it doesn't matter what the medium is. The formulae are derived from plant extracts. Some modern conservation uses harmful chemicals, surfactants and solvents that break down the cellulose in the paper causing cellular degridation, resulting in ultimate disintegration.