Bill Tindall, E.Tn.
The literature says it is for removing dyes, no mention of pigments. MSDS reveals how it works. It is simply a bleach in a glycol solvent. More mild on the hands than chlorine bleach but probably not as effective. I'll be surprised if it bleaches printing ink, at least the ones for photograph prints. But let us know if it does as that will be useful knowledge.