Indelible /(?)/

In·del·i·ble

Indelible

a.
  1. That can not be removed, washed away, blotted out, or effaced; incapable of being canceled, lost, or forgotten; as, indelible characters; an indelible stain; an indelible impression on the memory.
  2. That can not be annulled; indestructible. [R.]
    They are endued with indelible power from above.
    — Sprat.
    Indelibly stamped and impressed.
    — J. Ellis.

Phrases & Compounds
Indelible colors
fast colors which do not fade or tarnish by exposure.
Indelible ink
an ink not obliterated by washing; esp., a solution of silver nitrate.