Cox started experimenting with the making of multi-colored prints on his own litho press at the beginning of the 1950's.  Dissatisfied with the results so obtained, in 1952 he travels to Paris to work with the famous Moulot printing atelier.  Here Cox could take advantage of ideal printing conditions and expertise, as had artists like Villon, Chagall and Giacometti, and he produced fine color lithographs without being overly encumbered by technical details.  Some splendid works were achieved there, like the calligraphic Verhuizing ’s avonds (Evening Removals).  In 1953 Cox shows a selection of his lithographic work in Amsterdam.  Later the exhibition would travel to Indonesia, and a catalogue of Cox's graphic work is published with a text by J.H.W. Veenstra to accompany it.