Dark contrast (SC) Another new G7 variable in this version is the dark contrast (SC). In production, SC can quickly check the dark tone level in NPDC. SC replaces the printing contrast value of CMY monochrome. SC needs to be measured twice, once for CMY (SC_cmy) and once for single black (SC_k). Measuring SC_cmy First measure the neutral density (ND) of the CMY overprint gray patches (75C, 66M, 66Y), and then subtract the neutral density of the paper to get SC_cmy. SC_cmy = ND (75C, 66M, 66Y)-ND (paper) The SC_cmy value will change with each machine, and can be automatically calculated by IDEAlink software. Measuring SC_k Measure the density value of the 75% black block first, and then subtract the paper density to obtain the SC_k value. SC_k = ND (75k)-ND paper) The SC_k value will vary depending on the machine, and can be automatically calculated using IDEAlink software. SC absolute value If the SC includes the paper density, the SC absolute density value of the paper can be obtained, and the SC can be controlled only by measuring the gray block once. such as: If the paper ND = 0.09, SC = 0.97 SC absolute density = 0.09 + 0.97 = 1.06 (only for this type of paper) L * units represents SC absolute density If L * units is used instead of density to represent the absolute SC density, a Lab reading can be used to simultaneously measure gray balance and brightness. The L * SC value can be calculated automatically by IDEAlink software. Note: It is best not to use the "relative" L * value to represent or measure SC, because the spectrophotometer does not allow calibration on an arbitrary substrate, and if the paper is not a standard 95L *, then the relative value of the measured L * will be Makes no sense. Vegetable Cover,Winter Vegetable Plant Windscreen,Plant Cover Frost Blanket,Greenhouse Film Agricultural Supplies Changzhou MD International Trade Co., Ltd. , https://www.mdgarden.com