howtocuresplitends

I'm oftentimes asked nigh what AM/XM halftone screens are equivalent to a sure enough FM shroud - i.e. "What AM/XM shroud is equivalent to a twenty micron FM screen?" There are ii ways that this halftone screening equivalency is commonly measured. One is equivalency of item rendering - the mightiness of the screening to homecoming icon detail. The other is lithographic equivalency - how they perform on press lithographically. Note that inwards both cases, because the respective screening applied scientific discipline is in addition to thus different, equivalency tin exclusively hold out an approximation. Equivalency of item rendering Since halftone dots degree the printed icon - to a greater extent than dots per linear inch translates into to a greater extent than item that tin hold out rendered. With an AM shroud the item rendering mightiness is specified inwards lpi (or lpc) - i.e. halftone dots per inch (e.g. 175 lpi or lx lpc). Since an FM shroud has no ...

[click "Play" to persuasion animation - may accept a minute to buffer] Note that the dots are non precisely the same at each percentage. In part, this is to avoid unmarried channel moiré. Also regime notation that inward the really calorie-free tones (as good every bit inward the darkest tones) every bit you lot piece of job past times away through the tones, sometimes at that spot are dots i pixel is size alongside gaps betwixt them which are together with then fill upward alongside to a greater extent than i pixel sized dots. Then piece of cake unopen to of the unmarried pixel dots piece of job past times away ii pixel dots mixed inward alongside the unmarried pixel ones. This is because a RIP volition merely picture amount private pixels to shape a halftone dot. So, inward the instance of a 2,540 dpi device, each pixel is 10 microns inward size (10.6 microns for a 2,400 dpi device). Therefore, if, for example, the the point diameter needs to survive fifteen microns ...

To make upwards one's remove heed which enshroud angle to role when a screened PMS/spot color overprints a 4/C procedure ikon y'all volition postulate to expect carefully at the ikon that y'all volition last overprinting. The basic dominion is to role the enshroud angle of the to the lowest degree prominent (or missing) screened procedure color that volition last underneath the screened spot color. For example, if there's no screened dark nether the spot color - role the Black angle, if there's no Cyan role the Cyan angle, etc. Try to avoid using the Yellow enshroud angle because inward touchstone enshroud angle sets yellowish is solely xv degrees away from C or M. As a lawsuit moiré is e'er at that topographic point only it is normally non visible because the yellowish is therefore pale. The moiré tin instruct visible however, if the yellowish becomes contaminated - or if it is used for a nighttime spot color. For example, inward the graphic below, the...

An AM/XM halftone enshroud has a builty-in conflicting ink/water repose requirement on press. The highlight dot together with quarter musical note attain from 1-35% requires minimal H2O together with maximum ink inwards lodge to forestall those dots from existence washed away. The three-quarter musical note attain from 65-99% requires the contrary - a larger book of H2O inwards lodge to forestall the shadow dots from filling inwards together with disappearing. On the other hand, the mid-tone attain from 35-65% is to a greater extent than of a repose betwixt ink together with water. Halftone dots together with the tones attain they stand upwardly for are affected differently past times the status of the ink on press - assuming of course, that the plate, press, together with chemical scientific discipline are laid upwardly correctly. Unfortunately, if the press operator attempts to gear upwardly musical note reproduction inwards roughly areas, that built-in divergence inwards ink/water r...

When screens of cyan, magenta, in addition to dark are overlaid at their respective angles (105º, 75º, 45º) they course of report a moiré designing called a "rosette." If the printer is required to purpose a fairly coarse AM/XM halftone hide (e.g. 85-150 lpi (newspaper & periodical work) ), then, depending on the icon color content, the rosette designing tin conk visible plenty to last objectionable. One means to trim down the visibility of the rosette construction is to motility to a finer AM/XM hide which makes the rosette smaller in addition to thence less visible. However, if that is non possible, so changing the separation method mightiness last a feasible option. The bulk of RGB to CMYK icon conversions purpose "GCR" every bit the method (it is the default separation technique inward Adobe PhotoShop). This ensures that wherever C, M, in addition to Y inks are used dark volition last introduced. The effect is a real visible rosette construction every bit...