Frank Lloyd Wright and Charles Rennie Mackintosch were the pioneers of the holistic Organic Design movement. She turned their architectural designs into Gesamtkunstwerke, in which not only the building but also the interior was designed. As a result, the interior and exterior would form a harmonious whole for a more optimal experience that is in line with nature. Organic Design is in direct opposition to the formal International Style in terms of design language. According to Organic Design, design should result from rules that can be traced back to the laws of nature. Design must therefore match the environment and needs, not go against them. Within architecture, unity of nature and culture must be embodied and expressed. In Organic Design, flowing lines and synthetic (and therefore easy to shape) materials are often used. Due to a better understanding of ergonomics and anthropometry and the advent of digital design possibilities, this organic and plastic design movement flourished even more in the 1990s.