Anodising: Anodising is a process of forming a thick oxide layer of aluminium. This aluminium oxide coat over aluminium itself makes it resistant to further corrosion. During anodising, a clean aluminium article is made the anode and is electrolysed with dilute sulphuric acid. The oxygen gas evolved at the anode reacts with aluminium to make a thicker protective oxide layer. This oxide layer can be dyed easily to give aluminium articles an attractive finish.