A layer of lacquer is applied to cover the gold completely. It goes beyond the edges and center of the disc in order to prevent any peeling (as the layer of gold tends to peel easily and humidity might therefore infiltrate). This layer is baked under ultra-violet light for two seconds.
The lacquer is deposited using a fixed nozzle. It is then exposed to UV light for several seconds for perfect heat treatment. When the process is stable, it is checked once a day. The heat treatment must last long enough for the lacquer to be neither sticky nor overbaked. Since the gold layer and dye tends to peel, it needs to be properly covered, and the lacquer is applied all the way to the edge of the disc.