Replications of the lustre layers have been produced using laboratory-controlled conditions, based on a 13th century AD lustre recipe. The characteristics of the lustre layers obtained by using different paint and glaze compositions, thermal paths and atmospheres are summarised. The key parameters needed to reproduce the colours, composition and metallic optical response shown by medieval lustres are given. Analysis of the microstructural, chemical and optical characteristics of the reproductions gives a deep insight into the conditions needed for the production of lustre layers with different colours and shines. The necessary changes and improvements in the lustre process from the beginning of the lustre production (Iraq 9th and 10th centuries AD), through the Fatimid (Egypt 11th and 12th centuries AD) and later Syrian and Persian (late 12th and 13th centuries AD) productions are reviewed.