In Kritha Yuga men had great mental power and they could meditate ‘Pranava’ (Om or AUM) with full concentration. Here “A” represents Almighty; “U” represents Universe and “M” represents Man. Gradually man lost concentration and in Thretha Yuga, they began to worship natural forces like Agni (fire), Soorya (Sun), Vayu (air) and Jala (water) as representatives of super power. During Dwapara Yuga, systematic procedure of worship was evolved and followed.  In Kali Yuga to have mental peace, sasthra (science)gave importance to Namasamkeerthanam, Sath-Sanga, hearing of scriptures, worship in temples etc.  As far as common people are concerned their feeling of God is in idols. Great Masters believe God lives within them. But for ordinary people different types of idols were made in different materials based on different concepts. Idols are either self revealed (Swayambhoo) or made and consecrated. Syambhoo idols are considered as more sacred and important. The revelation of Syambhoo idols is associated with some strange occurrence.  There are instances where idols were recovered from rivers, streams etc. on revelations in the dreams of ardent devotees. The Vigraha (idols) made and consecrated are excellent artistic pieces either carved or mould according to the directions laid down in Silpa Sasthras (idol making theory).

Idols are made using different materials such as stone, metal, wood, Katu-sarkara, stucco, mud etc.

Stone Idols

Granite used for making idols are known as ‘Shila’. Shilas are classified as (i) ‘Purusha Shila’ (Male stone); (ii) ‘Sthree Shila’ (Female stone); and ‘Napumsaka Shila’ (Neutral stone). Purusha Shilas are used for making idols of Gods and Sthree Silas for Goddess. The Napumsaka Silas are used for carving ‘peethas’ (platforms). Silas, which spread spark when hit by chisel is considered as most suited for making idols. A shila selected for a particular deity should not be used for any other deity. The site so selected is subjected to purification ceremony known as ‘Shilaparigraha’.

Metal Idols

The Mathsyapurana contains the method of casting bronze images.  Bimbas (idols) are generally made up of Panchaloha (an alloy of five metals). Panchaloha contains copper, tin, silver, gold and iron.  These metals are melted and mixed on a prescribed proportion and the melted alloy is poured into the mould.  This is done on an auspicious day.

Wooden Idols

Though wooden sculptures are common in every prakaras of Kerala temples, idols carved in wood are very rare. Carving of idols is done normally in five types of woods. They are (1) Charalam; (2) Thunduka (Panachi); (3) Teak; (4) Varikka Pilavu (Jackwood); and (5) Devatharam.  In Kerala, among the above five, teak and jack wood are generally used.  The wooden images are treated with a liquid known as chanth manufactured by distilling the bark or root of teak. Applying the chanth on the idol is called chanthattam.  In some temples instead of chanthattam, the idols are painted with modern colours.  Before cutting a tree for the purpose of carving, permission of the tree is obtained by praying to the tree known as ‘Vriksha Pooja’. Utmost care should also be observed while cutting the tree so that it will not fall on the ground and it has to be taken to the work-site observing certain prescribed ceremonies.

Idols of Katu Sarkara Yogam

There are very few temples in Kerala where the idols are made of Kadu Sarkara Yogam.  An important thing to note is that the Bimba (idol) has to be made at the spot where it has to be installed.  Different raw materials have to be collected for the purpose. The method of making can be divided into six stages, viz.,  (1) making of the skeleton of the idol as per the measurement as specified in Thanthric Texts; (2) Ashta-bandha-lepana for properly fixing the skeleton; (3) Nadi-bandhana i.e., fixing of nerves at various parts of the skeleton from head to toe;  (4)  Mrtth lepana i.e., coating specially prepared medicated mud for shaping different parts of the body; (5) fixing of silk cloth resembling inner layer of human skin and (6) application of Kalkka – a thin natural medicinal covering for the protection of the body.

A very brief description of the above six stages are given below:

(1) Making of skeleton: - Good quality woods like Karingali, Devatharu and Chandanam (sandal) are used for this purpose. Different body parts are made with the above wood material and they are joined with the help of copper wires and copper plates.

(2) Ashta-bandha-lepana: - The materials such as Thiruvattaapasa (a particular gum obtained from a tree), Kunthirikkam, Guggulu, jaggery, Chenchelyam and Kavi are taken in the proportion of 4:3:5:1:8:3 and powdered and mixed with two part of oil and part of ghee and heated in an earthen pot. When it becomes near to a paste form it is taken out in a lukewarm condition applied all over the skeleton carefully.

(3) Naadi-bandhana: - To resemble the nervous system in the human body fine fibers taken from the coconut husks after due process is used in the skeleton for yarning the naadies.

(4) Mrtth-lepana: - Firstly soil from (i) dry land; (ii) marshy land (iii) desert are collected and cleaned. Then three types of Kashayam are prepared with (i) Karingali and Maruthu; (ii) Nalpamaram (Athi, Ithi, Arayal and Peral); and (iii) Kolarakku. The three type soils are put in three separate Kashayams in three earthen pots for 10 days. After that the dried mud is put in Thriphala Kashayam (kadukka, Nellikka and Thannikka) for another 10 days. Then 1/4th quantity of powdered river sand is added in each pot and mixed. Then barley, wheat and kaasavu are powdered and mixed at specified proportion. To arrive at the final process coconut water, Thiruvarrapasa, Kunthirikkam, Guggula, Chenchayam, honey, cows curd, Chukku, Pepper , Thippali, Ghee, Milk, Plavu pasa, kernel of Koovalam fruit, kunkumam, akil, kottam, gorochana, kaasavu oil, kasthuri, gold, silver, river sand, sea sand, clay from crab’s hole, sand from farmer’s plough, sand from bull’s hooves, sand from elephants task, water from the river Ganges, are used at different proportion at different stages and in different combination. The entire mixture is then put in a Kashayam of Ilippa tree fro five days. Then add small pieces of coconut husk, gums of koovalam and plavu to it. This mixture is applied on the skeleton and the desired characteristics and shape of the idol are achieved.

(5) Fixing of silk: - Pure silk is wrapped around all parts of the idol with the help of gum or latex to give a good protection to the mrtth.

(6) Application of Kalkka: - Equal proportion of powdered river sand, black sand, bloack stone or gravel found in river beds and Kozhipparal are ground daily for a period of one month in a Kashyam of Thriphala gum of Plavu and gum of Koovalam. This coating of the mixture is made on the idol. Ornamentation and decoration can be made on the idol using Kalkka. Application sanku (conch) powder will give the idol a whitening effect.

Katu Sarkara Yogam idols are not subjected to abhisheka.
A very famous deity made of Katu Sarkara Yogam is that Sree Padmanabha Swamy Temple at Thiruvananthapuram.

Stucco Idols
Stucco Idols or clay images are rare in Kerala, except in the border area adjoining to Karnataka. (Eg., Ananthapura lake temple in Kasaragode Dist).

Mud Idols
Mud Idols made of mud are also very rare in Kerala.

Measurement of Vigrahas (Idols)

There are 32 important Sanskrit works on sculpture in ancient times which have been stated in Maanasaaram. In addition there are 18 texts such as Isana, Chithrakasyapam, Prayoga Manjari, Peruhitham,Buddha-matham, Gouthamam, Kulalam, Vasishtam, Mano-kalpam, Bhargavam, Markandam, Gopalam, Naradeeyam, Kashyapam, Chithra-yamalam, Chitra-bahulayam and Desikam.

In North India, the sculptors follow different texts. The idols of Lord Shiva, Lord Vishnu, Lord Ganapathy and Goddess Bhagavathy are made observing the regulations and principles as laid down in the relevant Sanskrit texts. In Kerala these principles are observed strictly.