Attribution and conservation of the Portrait of Peter The First from The Tula State Arms Museum. Experience in application of consolidation mixture of protein and non-protein adhesives

The painting Peter the Great, a copy from the original by Jean-Marc Nattier, was in a deteriorated state when it arrived at the Department of Scientific Restoration of Easel Oil Paintings at the State Research Institute for Restoration. The absence of a stretcher and prolonged storage in a rolled-up position caused extensive damage, including numerous tears in the canvas and significant losses in the paint layer and ground. A breakthrough discovery was made during physico-optical studies in the infrared spectrum — an author’s signature and date hidden beneath surface layers. This unexpected find provided valuable insight into the painting’s origin and historical context. The restoration process was particularly challenging due to the ruined condition of the canvas, which had lost structural integrity. Both the front and back surfaces were covered in powdery dirt, and large areas of the paint layer were peeling. To consolidate the ground and paint layers, a mixture of plant- and animal-based glues was applied. A low-pressure table — without heating — was used to simultaneously eliminate canvas deformations, remove surface dirt, and secure the fragile paint and ground layers. Tears in the original canvas were mended thread-by-thread before being lined onto a new woven base and mounted on a exhibition stretcher. Darkened varnish layer was thinned and surface dirt removed, the painting's original colors were restored, and the author’s signature became visible again. Large areas of loss were filled with a colored ground and carefully in painted, ensuring a partial yet accurate reconstruction of the original image.