ALUMINIUMARTIKEL MED EN ANODISK OXIDBELAEGNING PAA OVERFLADEN OG FREMGANGSMAADE TIL FREMSTILLING AF EN SAADAN ARTIKEL

The invention provides aluminium articles having porous anodic oxide films coloured by means of an optical interference effect. In Figure 4, the article 10 carries a first anodic oxide film 12 with pores 14 enlarged at their inner ends 20 and containing deposits 22. The products may be made by growing a second anodic oxide film 26 underneath the deposits 22 which are preferably of acid-resistant material. X is at least 26 nm, Y is preferably at least 60 nm, Z is preferably 15 nm to 200 nm, (Y + Z) is preferably 75 nm to 600 nm, and W is preferably at least 15 nm.