ABSTRACT
During the meticulous restoration of “the Bargueño,” an exquisite gilded travel cabinet dating back to the 16th century and hailing from the historic Château de Pau in France, an intricate conundrum surfaced. It was a puzzle involving the presence of two superimposed layers bonded by the same adhesive, a quandary insurmountable by conventional restoration techniques. The physical-chemical attributes of the materials posed a formidable challenge in the quest for an effective remediation strategy. Analysis revealed a duality in gilding techniques; the wooden portions were adorned with water gilding, while the ivory sections exhibited oil gilding. To address this exceptional restoration challenge, a groundbreaking method was embraced. A feasibility study was conducted employing a pulsed Er: YAG laser operating at 2940 nm in a µs regime, meticulously applied to gilded ivory prototypes. This laser methodology facilitated the precise ablation of layers, completely circumventing direct material contact. The degree of precision could be finely tuned by manipulating laser parameters. The laser ablation assessments on prototypes, varying in gilding layer thickness, were executed under the vigilant watch of optical coherent tomography (OCT). This innovative approach permitted the meticulous removal of layers during the restoration process of the ornate twisted and gilded columns, unequivocally affirming its efficacy in the preservation of gilded surfaces.
