Graphic design was influenced by geometry at this time and the shapes of Modernism were exaggerated and played with. Stepping vertical boxes became popular in work of the designers: Weingart, Kunz and Bubbles. Rules of slick, clean-cut design were broken and original experimental designs were introduced. However, some of the concepts of Postmodernism were brought in at many times during the early 20th century, and actually fit in with the characteristics of the term. This adds to the vague nature and boundaries of Postmodernism as there are no distinct dates of when it began and finished there are arguments whether Postmodernism is still continuing.