Write a note on the Utsava Murtis tradition and Tamalana System with reference to ancient metal sculpture in India.

In the early medieval period, a great relationship of adoration and love was developed between devotees and the deities worshipped in the Brahamanical traditions. The human form of deities made it easy for the devotees to relate themselves to them. This led to the creation of the divine families, so that the people were able to easily engage themselves with their deities through their everyday lives.
Utsava Murtis Tradition of South India
According to the ritual texts, there are two kinds of utsavas. First is that take place as a regular part of worship, in which the deity may make a circumambulatory tour of the temple. Second is that which occurs once a week, month or year. The most important are the grand celebrations called Maha Utsavas that occur as annual celebrations.
The importance of these Utsavas is that the deity leaves the sanctum sanctorum and becomes approachable to all.
In the medieval period, a great tradition of utsava murtis, or festival images began. The deity, in many manifestations of the human form, comes out onto the streets. Sometimes the deity performs a journey to a place of pilgrimage or may be taken for a ritual bath or even to the seashore to enjoy the breeze.
In the 8th century, the Utsava Murthis were made in Bronze in Tamil Nadu. This tradition of Bronze sculpture reached its zenith during the Chola period. The themes of the images are eternal.
Unlike the European tradition of using models, the images were all made using mnemonic techniques, whereby the craftsmen were meant to memorise dhyana shlokas which describe the attributes of various goddesses and gods and they used the taalamana system of measurement to essentially visualise the image and then sculpt it out of their own imagination rather than using models. Taalamana is a complex system of iconography derived from the Shilpa Shashtra.
It is called Taalamana paddathi or Taalamana system, the system of measurements by Tala, the palm of hand.