Light-Marking Photographic Alternatives pg 527-530
During Solar printing you can use the double exposure technique with an aquatint screen. this will prevent the polymer emulsion from wearing away or washing out. First you must double expose the plate with an aquatint screen. This step allows you to retain extensive areas of deep black in the intaglio image. In print making this process is referred to as an “open-bite”. Basically the aquatint provides a textured layer which will suck up the ink in areas of white space creating a better tonal range.