The invention concerns a method for manufacturing of an object having phosphorescent properties, comprising the steps of providing an object having a surface made from aluminium or from an aluminium-based alloy and forming a layer of porous aluminium (hydr)oxide at said surface. The invention is characterized in that the method comprises the step of contacting the layer of porous aluminium (hydr)oxide with one or several solutions containing metal dopant ions such as to allow the metal dopant ions to bind to the layer of porous aluminium (hydr)oxide, wherein at least one of said solutions contains ions of at least one element selected from a first group consisting of calcium (Ca), magnesium (Mg), strontium (Sr) and barium (Ba), and wherein at least one of said solutions contains ions of europium (Eu). The invention also concerns an object obtainable by the above method.