OM&TA is the ontology of materials and techniques in art. It tries to formalize and represent the relationships between the external formal data about an artwork and its components as define by art criticism, with a particular focus on the relationship between the materials used and the techniques performed on them in order to obtain the final results.
Material of an artwork can be of various kind: the proper materials on which the artwork has been realized, accessories as frames and support, which are not the carrier of the main information, but still are part of the artwork as a whole, decorative materials etc.
The change of material reduces the pletora of techniques that can be performed on it, those are not strict rules, but consequences of the materials themselves, for ex. it is improbable that an oil painting would be performed on marble, since that material will not easily keep the colour on it surface.
This ontology tries to formalize the description of external data of an artwork trying not to just provide a list of classes useful for this representation, but to keep the relationships between its formal components.
In order to provide a proper formalization of all those relation we started by giving a definition in natural language of the main elements, starting from the definitions provided by Gianni Carlo Sciolla in the book Studiare l'arte. Metodo, analisi e interpretazione delle opere e degli artisti
, which provides a sum of all the aspect related to a work of art, from its objective characteristics to the autorial aspects.
The chapter 2, "I materiali", of the book is the one related on materials and techniques, and has been used as the starting point to build this ontologyen.: "The materials" and 3 "Le tecniche" en.: "The techniques".
According to the latest UNESCO classification of cultural heritage, this ontology can be applied to artworks which can be classified as "Tangible Cultural Heritage" and "Movable Heritage".
In order to define the materials, Sciolla reports the definition given by Formaggio:
"Si può chiamare materiale tutto ciò che per l'arte è dato in natura o è elaborato dall'uomo, ma che comunque nell'arte ritentra come dato fisico esterno"
en.: "It is named material everything that in the art is both given from nature or elaborated by the human being, but still is part of an external physical element."
The technique is defined as:
"l'insieme delle norme, dei precetti, dei modi elaborati dagli artisti lavorare i materiali nel corso del tempo, sperimentati nelle botteghe e nelle officine artistiche."
en.: the union of all the principles, rules and manners elaborated by the artists for the material processing over time, experimented in the workshops and artistic laboratories.