Welcome Jay. Exactly Black color will change depending on the value of Cyan, Magenta & Black or RGB if you are in RGB mode. For example, You have 2 black colors in Illustrator swatches one ( Registration Black) and the other one ( Black ) The registration Black is 100,100,100,100 in CMYK it appears darker and working well with transparency but the Normal Black is 0,0,0,100 in CMYK it will appear more gray with transparency and gradients, It made to color the small text to print in one plate.
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