The biggest drawback of using higher than necessary LPIs is the potential difficulty in getting adequate ink density from the smaller cells. The old rule of thumb was to run anilox at 4 x the plate screen. As plate quality has improved in its ability to carry and maintain smaller highlight dots, the standard has shifted to 5 x the plate screen in order to avoid dot-dipping. This has had a tremendous impact on print quality due to the vastly greater concentration of ink droplets applied over the surface area of the print. While higher linecounts enhance image resolution and highlight fidelity, they do so at the expense of ink carrying capacity. As long as you can achieve your desired spectro readings, you should be in good shape.
If you are struggling for color and find your operators cranking up the blade pressure, using excessive impression, or playing mad scientist with the inks, your cell capacity is not adequate and the negative ramifications will far outweigh the advantages of the higher linecounts. Excess blade pressure can cause premature wear to the doctor blades and anilox rolls. While blades themselves may not be all that expensive, the downtime to change them out frequently can add up to a sizable drop in productivity.
The anilox rolls represent a much larger investment, but long before you get to the point of replacement, you will find yourself pulling the rolls out more and more frequently for cleanings in an attempt to coax out a little more ink on press. Because cell carrying capacity diminishes as the rolls wear, it becomes more and more difficult to achieve color. Excessive and/or improper cleaning can also deteriorate the cell structure leading to ink pooling across multiple cells rather than contained within them. This results in inconsistent ink delivery and dirty plates, which only gets worse with subsequent cleanings.
Excessive impression causes plate dots to flatten out which magnifies dot gain and quickly damages highlight areas of the plates. Plates are also relatively inexpensive, but the downtime resulting from frequent (unnecessary) plate changes can decimate your press productivity.
Unnecessary ink manipulation can lead to premature drying, (which in turn can plug anilox rolls), color shifts during the print run, and unnecessary waste during subsequent make-readies trying to match color on similar jobs.
As you can tell, use of higher than necessary linecounts is a double edged sword. If you are able to carry adequate color without throwing off the rest of your process, you will benefit in terms of print quality. If you have to use improper settings or techniques to try to "force" out enough ink, you are asking for trouble.
If you are struggling for color and find your operators cranking up the blade pressure, using excessive impression, or playing mad scientist with the inks, your cell capacity is not adequate and the negative ramifications will far outweigh the advantages of the higher linecounts. Excess blade pressure can cause premature wear to the doctor blades and anilox rolls. While blades themselves may not be all that expensive, the downtime to change them out frequently can add up to a sizable drop in productivity.
The anilox rolls represent a much larger investment, but long before you get to the point of replacement, you will find yourself pulling the rolls out more and more frequently for cleanings in an attempt to coax out a little more ink on press. Because cell carrying capacity diminishes as the rolls wear, it becomes more and more difficult to achieve color. Excessive and/or improper cleaning can also deteriorate the cell structure leading to ink pooling across multiple cells rather than contained within them. This results in inconsistent ink delivery and dirty plates, which only gets worse with subsequent cleanings.
Excessive impression causes plate dots to flatten out which magnifies dot gain and quickly damages highlight areas of the plates. Plates are also relatively inexpensive, but the downtime resulting from frequent (unnecessary) plate changes can decimate your press productivity.
Unnecessary ink manipulation can lead to premature drying, (which in turn can plug anilox rolls), color shifts during the print run, and unnecessary waste during subsequent make-readies trying to match color on similar jobs.
As you can tell, use of higher than necessary linecounts is a double edged sword. If you are able to carry adequate color without throwing off the rest of your process, you will benefit in terms of print quality. If you have to use improper settings or techniques to try to "force" out enough ink, you are asking for trouble.
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