In 2012, during the preparation of the exhibition entitled 'Notre-Dame de Laon. Des ruines romantiques au renouveau gothique', forty plaster casts from the nineteenth-century restoration period were discovered. Administrative archives show that these types of casts were used by sculpture workshops such as those of Geoffroy-Dechaume or Tournier. The casts, designed for practical purposes, were used by sculptors to make a perfect copy of the original and are rare testimonies to this period of the cathedral's restoration. The casts that were found were stored and temporarily displayed in the cathedral's lapidarium during the 2012 exhibition. An inventory and scientific survey are in progress to identify the casts and locate the copies that were produced.