Seven years after Elector Max III Joseph of Bavaria established the Electoral porcelain manufactory, he ordered that all porcelains be marked on the underside – with an image of the Wittelsbach coat of arms with diamonds whose tips at the time progressed from the bottom left to the top right. Over the years, Porzellan Manufaktur Nymphenburg's trademark has adopted many different guises. But one thing remains: it is still pressed using a little stamp made from biscuit porcelain into the soft mass. A task that may only be assumed by the most experienced craftsmen and craftswomen who besides the coat of arms also impress their initials into the object and so express their personal responsibility for the quality of their product.
Despite the different semblance that the mark on the underside of the objects assumed over time, it always remained recognisable: the symmetrical shape is the result of two concave upward curves, the convex indents on the sides and the lines flowing in and out towards the tip at the bottom. The field is filled with a diamond relief.
The continuous changes to the style and heraldry of the shield are a reflection of the 260 years of the manufactory's history. The symbols help experts date the items. As with valuable Aubusson tapestries or papers with watermarks, Porzellan Manufaktur Nymphenburg's mark possesses the status of a seal of quality. It is a guarantee of the highest production quality and is recognised throughout the world as Nymphenburg's mark.
All figures are also assigned a model number, sometimes combined with a size code I/II and the number of the former. Items of crockery are given a three- to four-digit model number as well as a single-digit size number.