3. Other gilding – Processes

3.1 By broadcasting

Diffusion gilding, which can also include chop gilding, is a metal foil gilding process in which no intermediary is added between the substrate and the foil. It is the heat treatment, or the hammering that follows its application, that ensures the foil's adhesion. To guarantee rapid interdiffusion of the components, the substrate must be perfectly free of its oxide layer, either by chemical cleaning or polishing immediately before the foil is applied, or by etching the notches characteristic of the chopping process. Hammering on the notched base can ensure that the layer remains in place (the process is sometimes improperly called damascening), and can be sufficient on silver, which is not very oxidizable even in the absence of notches (figure