He no longer had the time to go to the local art school, but continued to draw, making caricatures of the teachers, and portraits of pioneers in the field of electricity to decorate the classroom.

In 1943 he entered the Royal Academy of Fine Arts of Antwerp, led by Baron Isidoor Opsomer, where one of his teachers was Jan Van Der Loo, a portrettist.

At the same time, Jef Nys started working at AFIM, a small animation study, with his fellow student Bob de Moor and Ray Goossens.

[4] After the war, he started working at 't Pallieterke, a satirical weekly newspaper, where he made political cartoons, illustrations, and his first comics.

[5] Jommeke started on 30 October 1955 as a one-page gag comic about a boy of about 6 years old, created for a very popular weekly parochial newspaper Kerkelijk Leven (a weekly circulation of over 500,000 copies on a population of less than 6 million), which had some redactorial pages (including the comic) for the whole of Flanders, and local pages for every parish.

[6] When Jommeke started appearing in the daily newspaper Het Volk on 1 November 1958, it changed into a comic story of 44 pages about an 11-year-old, with his friends and family.

Every day, he made 2 strips, in the tradition of the Flemish newspaper comics like Spike and Suzy and Nero, but aimed at a younger audience and with fewer political comments.

He also continued the production of biographical, more realistic stories, which are now published in 't Kapoentje, the weekly juvenile supplement to Het Volk.

[7] Nys also started in 1963 the fairytale comic Langteen en Schommelbuik (Longtoe and Wobblebelly), which ended after 11 stories because the work on Jommeke became too time-consuming.

Apart from the continuous stories in the newspaper, a few hundred weekly Jommeke gags appeared on the back cover of the Flemish comic magazine Ohee.

[8] When in 1965 Marc Sleen left Het Volk, Jef Nys took over his series De Lustige Kapoentjes for two years.

[10] Nys worked for many years solely for Catholic newspapers and magazines, and produced many biographies of religious figures.