Gilt leather is a composite material, consisting of goat, sheep or calf leather with superimposed a glair or gelatine mordant, metal foil (gold, silver or tin leaf), a paint layer and finally a varnish. The leather functions solely as a support. If it is too supple, the paint layer will be subjected to too much stress (it is essential that this be borne in mind when restoring gilt leather items). The stages of restoration are outlined: cleaning, lubrication (sorbitol, oil emulsion), cleaning the front. If red rot is present, an ammonia fumigation is carried out. In advanced cases of acidic breakdown, consolidation with monomers with delayed polymerisation is undertaken. Infilling of losses is carried out with vegetable-tanned skin, preferably calf, since it behaves chemically and mechanically in the same way as the gilt leather itself.