Hello to all. I have acquired a densitometro Heiland to carry out the calibrations PDN. I have a doubt: As each paper he/she does have a different color, are not all white pure, should I put to "or" my densitometro on the target of each paper to show him which the density of the pure target is?. Otherwise, the densitometro includes a calibration scale, black pure, half pure and gray target. It should gauge the densitometro to these parameters with independence of the color of each paper. Thank you. Excuses for my English, text translated by computer.