Thick from 0.1 to 0.3 microns, the gold leaf cannot be applied directly on the wood whose porous structure and possible cracks it would highlight. As the wood is also subject to dimensional variations, it must be isolated from the gold leaf by « buffer » materials, aqueous coatings called primers. In these numerous coats of primer (from 6 to 10), the gilder practises the « reparure »: he releases by means of curved irons (« fer à reparer » )the stuffed sculptures before carving them again meticulously. The last coat of primer is covered with a clay composition that the gilder throats with water before sitting his gold leaves on it. This plate allows the gold leaf to be polished with agate stone in order to obtain « burnished » shine, typical of water gilding, and to play with the volume effects.
