A mark applied to the forehead in sandalwood paste, turmeric, kumkum, or ash — worn after worship, at festivals, or as an ongoing sign of sect and devotion.
चलन-बलन · Chalan-Balan
The exact shape and material of a tilak traditionally signals sectarian affiliation, a vertical U or Y shape in sandalwood paste for many Vaishnavas, three horizontal lines of ash for many Shaivites, and a simple red kumkum dot common across traditions and, for many women, worn daily regardless of sect.
Applied at the point traditionally held to correspond to the ajna chakra, the 'third eye' between the brows, a tilak is offered to worshippers after temple rituals nearly everywhere already covered in this site's Tirtha & Devalaya chapter, marking that a person has received the deity's blessing before they leave.