Exposure Reciprocity in Screenless Positive Plate Lithography

ABSTRACT

Although the theory and earlier studies of screenless photo-lithography have suggested that reciprocity exists in respect of the light intensity and the duration of the exposure of the printing plate when sensitised with quinone diazide ester, the work relates to a purpose designed test. The results establish that reciprocity prevails over at least a six fold range of intensity or of duration. The supplementary evidence given suggests that good agreement occurs when as much as a 25 times variation in intensity and duration occurs.