a) Background Tint and Unwanted Specks – One of the most common problem with laser polyester plates is background toning caused by toner scatter from the laser printer on the plates. This problem becomes acute when the printer is running out of toner. Printing a few blank pages can help solve some cases where the toning is caused by dirt deposited inside the printer. Blank pages should also be run through the printer after a paper jam to clean the printer.
b) Misregistration – Registration is critical for jobs which demand more than one colour. If two colors are to be printed then two master plates have to be printed, one for each of the colors. Now the colors have to be printed on the plate such that their placement is accurate. Laser printers perform poorly in this. Exceptions are some high end laser printers such as Xante’s Platemaker series. These printers perform exceptionally well with polyester plates but both the plates and the printers are more expensive than the ones we get from vendors like HP for printers and Technova or Hurst Chemicals for plates. Xante uses its own plates known as Myriad Plates. Inkjet plates perform better in registration issues as the plates tend to be more stable and there is no heat as in the case of laser technology which might affect the plates.
c) Poor Printing of Solids – Areas in plates where there are a heavy concentration of a particular ink are known as solid areas. Laser printers again fail in this test too.
d) Stretching of Plates while Running in an Offset Machine – This is yet another problem which occurs with most of the laser plates.
e) Long Runs not Possible : Laser plates are limited to short run production usually in a few thousands. The toner on the plates tends to come off after some thousand impressions.
f) Laser Plates are Use and Throw : Laser plates are difficult for reuse as the toner comes off the plate after one time use.
Posted under Offset Printing
This post was written by admin on August 22, 2008
Good post.
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