Mosaic conservation practice went through a significant evolution in the past decades. Fifty years ago mosaics were considered as single objects, without a context, and interventions were carried out without adequate planning. Few options were considered in conservation strategies, and detachment was basically the only options taken into consideration. Professionals working on mosaics were essentially craftsmen, workmen and builders; the materials used were limited to cement, gypsum and glues. This presentation debates the change of philosophy and practice of mosaic conservation that shaped the current state of the art in the profession.