The Maori Moko, isn't acually a Tatau only..in this video he's talking about the grooves, which is how the original Maori Moko were down.

It's actually a scaring type of Tattoo or Tatau, which is probably the first in the world. The scaring Moko can be seen in old historical photos inside Aotearoan history.

Each ink line on the face is grooved or scared, then the ink settles inside the groove. Very painful and very beautiful.