 Heatage is an automatic technique developed and used by David Hare in which an exposed but unfixed photographic negative is heated from below, causing the emulsion (and the resulting image, when developed) to distort in a random fashion.In addition to its obvious meaning of writing that is illegibile or for whatever other reason cannot be made out by the reader, indecipherable writing refers to a set of automatic techniques, most developed by Romanian surrealists and falling under the heading of surautomatism.Examples include entoptic graphomania, fumage and the movement of liquid down a vertical surface.