Jakob Mattner, Zwielicht, 1985/2010, Glass, light, Dimensions variable, Photo: Alex Delfanne, Jakob Mattner, Zwielicht, 1985/2010, Glass, light, Dimensions variable, Photo: Alex Delfanne, Jakob Mattner, Untitled, 1981, Crayon, water on watercolour paper , 35,8 x 47,8 cm , Photo: Alex Delfanne, Jakob Mattner, Untitled, 1981, Crayon, water on watercolour paper , 35,8 x 47,8 cm , Photo: Marcus Schneider, Jakob Mattner, Untitled, 1981, Crayon, water on watercolour paper , 35,8 x 47,8 cm, Photo: Marcus Schneider, Jakob Mattner, Untitled, 1981, Crayon, water on watercolour paper , 35,8 x 47,8 cm, Photo: Marcus Schneider, Jakob Mattner, Untitled, 1981, Crayon, water on watercolour paper , 35,8 x 47,8 cm (each), Photo: Alex Delfanne,