In the corporate archives of Sphinx and Société Céramique, deposited with the Sociaal Historisch Centrum voor Limburg (www.shclimburg.nl) in Maastricht, a veritable treasure grove of pattern books has been preserved. In these pattern books the potteries collected the various designs that could be applied on their range of earthenware products. The books served as examples for the decorators in the factories, but salesmen and sales representatives sometimes made use of the books as well, to show their customers the decorations the company could supply.  

The major part of the designs originate from Petrus Regout's company, that since 1899 went by the name of Sphinx, and from the Société Céramique. The two firms merged in 1958. The archives also contain a few designs from other companies of which in most cases it is not clear how they ended up in the Sphinx's archives. A number of print designs from the NV Faïencerie de Nimy in Nimy-les-Mons in Belgium are also included. This pottery was taken over by Société Céramique in 1921.

The designs that have been preserved, date from between c. 1850 and 1969. This collection, consisting of almost 18.000 items, is included in its entirety in The Memory. It is not possible, however, to present this collection as a rounded piece of research. The collection is too extensive and diverse for this, and there are too few detail studies available about the use of the various decoration techniques by the Maastricht potteries.
The collection's inclusion in The Memory is meant primarily to make the collection of preserved designs accessible to a wider audience.

Researchers who wish to know more can consult the archives at the Sociaal Historisch Centrum voor Limburg and the earthenware and model collections owned by Continium and the Municipality of Maastricht. Most of the collection of Maastricht earthenware has been digitized, and is available online.