The Royal Dutch Delftware Manufactory "De Porceleyne Fles", established in 1653, is the last remaining Delftware factory from the 17th century. The world famous original Royal Delftware is still entirely hand painted according to centuries-old tradition.

Delftware painters paint the traditional decorations on the articles entirely by hand. This is done with brushes made of the hairs of martens and squirrels, and black paint containing cobalt oxide. The cobalt brings about a chemical reaction during the firing process, changing the colour from black to blue. The paint is based on water, enabling the painters to create various shades of blue by adding more or less water. Each piece is unique.