In Hindu tradition Vaishnavas are the devotees who worship Lord Vishnu in his various forms. The Vaishnavas traditionally wear the Urdhva Pundra made of gopi chandan as tilak. This is golden yellow in colour made of sandalwood paste and in the form of letter “U”.
By wearing this tilaka, the devotees identify their body as the temple of the Lord and get the blessings of Lord Vishnu.
It is believed that by wearing this tilaka, not just the wearer , but also the person who sees this tilak marks is immensely benefited.
While applying the tilak, devotees chant the twelve holy names of Lord Vishnu and hence are protected by the Lord himself. It would constantly remind the person of Lord Vishnu and keep him connected with the supreme energy. Also it is beneficial for the community because any person who sees this tilak also gets reminded about Lord Vishnu. Devotees of Lord Krishna wear this kind of tilak religiously.
Many Vaishnavites also add a red mark in between the two white lines of the tilak. This is to include Goddess Lakshmi who is always present along with Lord Vishnu. The Iyengar community is especially known for this kind of tilak. The two white lines denote Vishnu pada which are the foot prints of Lord Vishnu and it is believed that Goddess Lakshmi would always be present near the foot of Lord Vishnu to serve him.