From 1923 to 1926, he produced his own English-named avant-garde magazine The Next Call, which, like other works of the period, included collage-like experimentation with typefaces, printing blocks and other printers' materials.

Among the most fruitful contacts were with Theo van Doesburg, Kurt Schwitters, El Lissitzky and Michel Seuphor, the last of whom exhibited a print of his in Paris.

In 1929 he was able to visit Cologne and Paris, after which he developed a new printing method, applying the ink roller directly to the paper and then stamping to achieve unique effects on a simple handpress.

On 13 March 1945, the Gestapo arrested Werkman, executing him by firing squad along with nine other prisoners in the forest near Bakkeveen on 10 April, three days before Groningen was liberated.

[11] Just before World War II the museum director Willem Sandberg, who was originally trained as a typographer, had paid Werkman a visit and even arranged for him a small solo exhibition in Amsterdam in 1939.

Werkman Foundation was set up to promote awareness of his work and its large collection of prints, drawings, paintings and letters was transferred on permanent loan to the Groninger Museum.