Vatteluttu was in general use, but was not suitable for literature where many Sanskrit words were used. Like Tamil-Brahmi, it was originally used to write Tamil, and as such, did not have letters for voiced or aspirated consonants used in Sanskrit but not used in Tamil. For this reason, Vatteluttu and the Grantha alphabet were sometimes mixed, as in the Manipravalam. One of the oldest examples of the Manipravalam literature, "Vaishikatantram" (, "Vaiśikatantram"), dates back to the 12th century, where the earliest form of the Malayalam script was used, which seems to have been systematized to some extent by the first half of the 13th century.