Today, money is constantly being forged to forge with the help of modern copiers and scanners. For the purpose of increasing the number of counterfeit banknotes, designers are trying to put as many graphic protections on banknotes, to decrease forgery. There are several types of protection on banknotes, from the selection of materials of bills, the use of different printing techniques. In the past, there were no digital printing techniques. Notes were ensured from counterfeiting by artistic hand engraving. Today, with developing digital line graphs, it is more difficult for counterfeiter to copy the bill, because he is not familiar with the exact parameters that are used to obtain the line. This paper will describe the line graphics that are used to protect banknotes, and portraits of the existing banknotes. It will be described, among the other line protection elements, the process of making rosettes, sinusoidal and linear typography. Making portraits using line graphs will be explained using specially developed PostScript programs. Using PostScript, in the experimental part of the work, it will be prepared several samples of the line graphics, which will have different parameters. By changing the parameters in the samples, the quality of linearization will be studied.