This International Standard specifies a method for the determination of the tinting strength of carbon black relative to an industry tint reference black. The method is based on the use of five different commercial instruments. Other instruments may be used if the test results for the standard reference blacks are within the control limits given in ASTM D4821. NOTE The Densichron reflectometer and the Meeco Colormaster are no longer commercially available, but the procedures have been included for the benefit of those who still use these instruments.