line intaglio

…is the poor resolution of lines in the engraving of the bill. The line-intaglio process used for the printing of bills produces a distinctive sharpness of fine lines and readily discernible differences in ink thickness. Genuine bills have another element that is difficult to imitate: the use of a distinctive…

…are of two general types: line intaglio (sometimes referred to as copperplate gravure), in which the ink-retaining image consists of discrete lines that may vary in width and depth; and gravure (also known as rotogravure), in which both continuous-tone and line copy are reproduced as a series of tiny cells…