With one glaze imperfection in one corner, this is a production mistake. I have been an antique dealer since 2002 and specialise in antique tiles (Medieval, Portuguese, Spanish, Delft, Art Nouveau and Art Deco) and also Dutch Delftware. You can meet me at tile fairs in Germany: stadt Zons in March or in September in Boizenburg and der Elbe. I also go to England every year for the tile fair organised by the TACS. The fair in England always takes place on the first Saturday of October in Nottingham.