Color Newspaper Printing Quality: New and Old Network Technology Applications (3)

XM uses a special algorithm that perfectly solves the AM to FM transition algorithm: When the AM to FM transition, the FM random point continues the angle of the AM point, completely eliminating the transition marks between the two (see the figure below).

The XM network uses the concept of “minimum printable dots”: when the medium shifts to the bright (dark) transition, the dots are small (large) to a certain degree, and no longer continue to be smaller (larger), but are used to change the dot distribution. Density to express the level, always make the size of the outlets to meet the technical requirements of ordinary printing, so as to truly achieve 1-99% outlets in the print.

The figure above shows that: 180lpi XM dots are at 8%, 2% and 1% are the same size, express the level by reducing the distribution density of dot: the same method (white point) can be used for 92-99% of the Outlets. 1801pi XM minimum dot is greater than IOOlpi, 2% of the AM dot, if the printer can copy 100lpi, 2% of the AM dot, you can completely copy 180Lpi, l-99% of XM dot.

AM network to FM network conversion point calculations. The conversion point from AM to FM is related to the size of the smallest printable point, the number of screens, and the resolution of the output device. It can be expressed by the formula: Dot%=100% x min dot size x (lpi/dpi)x (lpi /dpi).

Comparison of XM outlets and AM outlets. The figure above shows that: at the time of printing, the 180 lpi amplitude modulation is lost in the high-light part of the network because the dots are too small for the printer to copy; and 180 lpi XM dots can completely duplicate the dots of the highlight part (which can also completely duplicate the dark tone part), Because the outlets always maintain the printable dot size.

2.XM application
The famous foreign graphic arts company Agfa, has launched Sublima outlets using XM technology, and has been successfully applied in many newspaper printing factories in Europe and the United States, reflecting very good results. In the domestic newspapers such as the Zhejiang Daily, Sublima was also used. On the domestic SSC presses, 170 liters of fine-clothes advertisements were printed using domestic newsprint and ink, which was highly valued by advertisers.

Source: Hubei Daily Newspaper Group