Core is a series of flat vessels inspired by prehistoric African building techniques. Willem has been fascinated by vessels, because they have such a clear and easy function, hold and transport water. It also was a canvas for humanity to express themselves. In ancient times, every tribe had their own specific shape in vessels. In a research of expressing himself through a new material, he found a challenge by developing a new form language. Because in Willems opinion, a lot of design is missing this freedom of expressing nowadays. All the pieces can changed with the glazing.