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.
The early practice of writing the initial lines or even the entire text of a volume in gold or coloured inks, and of staining with purple and of gilding the vellum, while it undoubtedly enhanced the decorative aspect, does not properly fall within the scope of this article; it concerns the material rather than the artistic element of the MS. (See Manuscripts, Palaeography.) It will be seen, then, that in the earliest examples of book decorations we find the germs of the two lines on which that decoration was destined to develop in the illuminated MSS.
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."