Netilat Yadayim with dirty hands

Hi,

Washing one's hands ritually for bread is ineffective if one's hands are dirty. However, "dirty" means that there is a physical substance interfering between one's skin and the water. If one's hands are stained, as with ink, but the skin is smooth and exposed entirely to the water, then one may wash ritually.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 2:110)

Have a great day,
Mordechai