Blue milk jug from Gien, Delft collection, in perfect condition. 
A Gien piece is of good quality, with a fine finish. Some of its decorations are typical, such as peony, cashmere or Gien blue.
This type of earthenware is easily recognised by the ‘Gien’ mark on the back of the piece. This is an engraved inscription, either handwritten or in the form of a small drawing. The castle mark is one of the best known.
This inscription makes it possible to identify the period or date of production of the earthenware with precision. The stamp on the pot au lait dates from between 1960 and 1971.