Sanna Lindström came to Karl Andersson & Söner to do her thesis on Carl Malmsten School. She made an open shelf / room divider, which consisted of a number of identical units. By self-stacking in different ways, you could get a variety of heights and shapes. In the development process the shelf got more sections, pivotal support and base and top panel. In 2009 the production started. Sign is a highly flexible and varied shelf that can be used as storage for books and binders, as a TV or shoe rack or as a room divider in homes or offices.