At the beginning of 1921 a new department was established for the printing of wallpaper. In 1929, the production of wallpaper by Brepols had amounted to this six millions roles. To overcome the trade restrictions imposed by the customs authorities of the United Kingdom and France in 1932, in Halluin (France) the "Société Française des Papiers Brepols" was created, in order to not to lose this important market. In 1945, baron François du Four died and his son Jean du Four succeeded him as President of the Management Council of the company. The special paper production were grouped, in 1960, in a new company, the "N.V Copa", in which three companies of Turnhout merged their business. In 1967, this business activity was taken over by the newly established company "N.V Turpa", together with the departments for colored paper of Biermans, Van Genechten and Copa. In 1970, Brepols, Biermans and Van Genechten, brought together their playing card business and created the company Carta Mundi as a joint venture, a world leader in the production of playing cards. More and more the company printed and bound books for other companies, due to the large decline of the need for church books caused by the Second Vatican Council. When the location of an industrial building in the centre of the city of Turnout could no longer be justified, an area of 7 hectares was bought in an industrial area outside the city and the first construction phase of the new building started in June 1969. In 1971, baron Louis de Cartier de Marchienne took over as the President of the Management Council. Under his leadership, the second phase of the work was completed in 1973, so that in 1974 the company moved to its new location. The site was further extended in 1989 for the expansion of the company. But the tide turned and the company, which employed at its heyday some 2200 people, was split up in 4 separate smaller companies. In 2003, two companies of the group filed for bankruptcy. The publisher and a part of the book binding activity continue to exist. At present it employs still about 200 people. In academic circles Brepols is particularly well known as the publisher of Greek patristic and medieval Latin works (in the Continuatio Mediaevalis) in the Corpus Christianorum series, which is in some respects seen as the successor to Migne's "Patrologiae cursus completus". Brepols has also replaced Herder as the publisher of the bilingual German patristic and medieval collection "Fontes Christiani".