Does anyone know how to make an eradicator? I mean, what substances erases the most common inks, for examples Parker Quinks.

Ink eradicators actually don't erase inks, they actually just disrupt the structural geometry of the organic die so it no longer absorbs any light (normally...dyes absorb the complementary color to the one you see and reflect the rest back). Typically, eradicators are made of a compound that can provide sulfite or hydroxide ions in a reaction with the central carbon molecule of the dye. Surprisingly, the effect of an eradicator can be reversed by a reaction with an aldehyde.

Thank you. I've learnt something new. I have always thought a substance in the eradicator attacked the dye making it invisible.

Wow!