A method for the production of metal sheet including a substrate having two faces, at least one of which is coated with a metal coating including between 0.1 and 10% by weight of Mg and optionally between 0.1 and 20% by weight of Al, the remainder of the metal coating being Zn. The method includes at least the steps of providing a steel substrate having two faces, depositing a metal coating on at least one face hot dipping of the substrate, solidifying the metal coating, applying onto the outer surfaces of the metal coating an aqueous solution having a pH of 7 to 13 and including a magnesium ion complexing agent, for which the dissociation constant pKd of the complexing reaction of the agent with the magnesium is greater than or equal to 2, and to the metal sheet obtainable with this method.