The state of preservation of ancient monuments of religious art, which is by no means satisfactory to date, urgently requires the use of modern methods of material and technical research for their restoration at all levels, from the base to the paint layer. The problems that have arisen in church art are also relevant our days, where, along with the successful reconstruction of ancient painting techniques (mosaics, encaustic), sometimes the latest materials and technologies are used uncontrollably, questionable from the point of view of the future life of monuments. This collection is devoted to the search for answers to these questions, the authors of which, without pretending to be exhaustive topics, offer their solutions.