"De Kat" is the last windmill in the world to use wind energy to turn rocks into paint pigments, as it was done nearly 400 years ago. Two huge grinding wheels weighing ten tons in total grind a variety of hard rocks for hours, turning them into colored dust.
The mill is now the last link to the original method of making paint, before the process was industrialized around 1850. Many Dutch masters produced their most famous works during the Dutch Golden Age, in the seventeenth century.