Editing Anodizing (section)

===Borate and tartrate baths===
Anodizing can also be performed in [[borate]] or [[tartrate]] baths in which aluminium oxide is insoluble. In these processes, the coating growth stops when the part is fully covered, and the thickness is linearly related to the voltage applied.<ref name="Edwards"/> These coatings are free of pores, relative to the sulfuric and chromic acid processes.<ref name="Edwards"/> This type of coating is widely used to make electrolytic capacitors because the thin aluminium films (typically less than 0.5 μm) would risk being pierced by acidic processes.<ref name="sheasby ch7"/>