I left the internal space empty, precisely with the idea that the viewer would fill it with imagination. Therefore, it is not the mark on the sheet of paper which is the work, but the action which must also be involved. In that moment it is not possible to distinguish where the work resides. Is it in my drawing, or in my imagination? Or between the two! This idea has fascinated me throughout my life...With the result that the action itself takes on the character of a work.

Franz Erhard Walther