This International Standard specifies a method for measuring densities of first generation silver-gelatin microforms. It specifies density values for different qualities of documents. It applies to source document negative-appearing microforms. It does not apply to microforms for technical drawings which are dealt with in ISO 3272-2, or to diazo and vesicular films which are the subject of ISO 8126, or to COM microforms which are dealt with in ISO 8514.