The fading of metallogallate inks is often due to a transformation of carboxyphenolic acids (from the hydrolyzable tannins in the ink) into products which cannot form complexes with the traces of metallic oxides (from the ink) remaining on the paper or other support. Faded ink can be regenerated by optical methods (temporary revelation) or chemical methods. Three efficient and safe chemicals used for ink regeneration -- gallic acid, 8-hydroxy-quinolene, and ammonium sulfate -- were studied. Intensity of regeneration was found to be a function of the nature of the support and the quantity of metallic oxides remaining on the support. However, ammonium sulfate was difficult to apply and gallic acid produced variable results.