Anodizing is an electrochemical process that creates a thick oxide layer on an aluminum surface. The anodized layer protects the aluminum surface from scratches and corrosion. The anodized layer is white, but it can be dyed many different colors. When the dyed surface is exposed to a CO₂ or fiber laser beam, the energy from the laser beam bleaches the dye and exposes the bright white hue of the anodized layer. Laser marking anodized aluminum creates an indelible laser mark without diminishing the protective quality of the anodized layer.