Ham, J.C. Jan van 

Jan van Ham was jointly-founder of De Vier Paddenstoelen/ The Four Mushrooms between 1923 - 1942 , thinner pottery produced because of Van Ham, since 1930 more sober simplified ceramics in model and decoration. Vases get straight shapes like sphere, funnel or cylinder models with glaze experiments.

Potter Jan van Ham makes his pottery art between 1945 till 1965 in workshop 't Bolwerk, started in the beginning of 1900 at Zuid Holland, St. Lukas, Zenith and Petrus Regout. Mark/backstamp: Signed with Ham and 't Bolwerk. Brother of W.A. (Wim) van Ham, Zenith.