Certain kinds of copying inks are greatly improved by the substitution of glycerin, in part or entirely, for the sugar or honey usually added.
US kimono (garments) appeared, in which inks of several colors were made use of; but these were only employed in turn for single printings, and in no case were two of them used on the same print.
It is certain, however, that the mere use of colored inks must soon have suggested the combination of two or more of them, and it is probable that examples of this will be discovered much earlier in date than those known at present.
One inks the type-forme and keeps a sharp look-out for any inequality of inking, and sees generally that the work is being turned out in a workmanlike manner.
During the interval between taking off the printed sheet and laying on the next one his partner inks the type surface with a roller which carries just sufficient ink properly distributed to preserve uniformity of " colour."