Studying the state of decay.
verb: (of organic matter) rot or decompose through the action of bacteria and fungi.
noun: the state or process of rotting or decomposition.
synonyms: decomposition, rotting, going bad, putrefaction, putrescence, putridity, festering, spoilage, perishing, withering, shrivelling; rot, mould, mildew, fungus, corruption, rot, rotting, corrosion, corroding, decomposition; caries, cavities, holes
Oil paint, acrylic paint, charcoal, chalk, pencil