Thermal Ink

Thermal Ink is an ability in Splatoon 2.

Thermal Ink reveals the location of players that the user deals damage to with the user's main weapon as a 'direct hit' (meaning that indirect Blaster blasts or indirect hits from a Sloshing Machine or Explosher do not count in this case), for about 16 seconds. Tagged players are revealed via a white silhouette, only to the user and only while roughly 150 DU away from the tagged player and only while the tagged player is not submerged in ink.

Thermal Ink is most useful for main weapons with long range that tend to hit opponents but not quite splat them, such as a Jet Squelcher. Thermal Ink should not be used on weapons with short range or weapons that splat opponents quickly, such as a Sploosh-o-matic. This is because in these interactions, either the ability user or their opponent is likely to be splatted, invalidating the ability either way.