Print problem - bigger dots (Kodak Evo, Maxtone, chinese plates)

[KamilT]

Hello friends,
please, can you help me with strange behavior we saw on printed magazine ...
There are some stripes on printed page, and i mean on one page from eight on signature, and on particular place on this page, all others pages are OK.
This artefact is exactly same through entire print run, so probably this is not problem with blankets, washing etc.
Attached is link to zip file with images, photos of page and pictures from microscope - you can see, particularly on the blurred images, that there are some darker areas, where cyan dots are considerably bigger.
Anybody have any idea why this can occur? This happened just in one case, we are not able to reproduce this behavior.
Kodak Evo 5, Maxtone 175 lpi, Magnus 800 Quantum, plates Huaguang positive thermal plate.
many thanks, i appreciate any advice,
Regards,
Kamil Tresnak

 

[gordo]

Hello friends,
please, can you help me with strange behavior we saw on printed magazine ...
There are some stripes on printed page, and i mean on one page from eight on signature, and on particular place on this page, all others pages are OK.
This artefact is exactly same through entire print run, so probably this is not problem with blankets, washing etc.
Attached is link to zip file with images, photos of page and pictures from microscope - you can see, particularly on the blurred images, that there are some darker areas, where cyan dots are considerably bigger.
Anybody have any idea why this can occur? This happened just in one case, we are not able to reproduce this behavior.
Kodak Evo 5, Maxtone 175 lpi, Magnus 800 Quantum, plates Huaguang positive thermal plate.
many thanks, i appreciate any advice,
Regards,
Kamil Tresnak

First of all, I would like to compliment you on your excellent documentation of your problem. Very well done.

I can tell you what I don't think is the problem. It's not Kodak Evo 5 (it doesn't look like an issue that a native file could have nor what a RIP could create), Maxtone (other than the 1-5% dots Maxtone is the same as Creo/Kodak AM screening), or the Magnus 800 Quantum (lasers issues are much more consistent). The printing looks excellent (and no background tinting) so I doubt that it's a press problem.

That leaves the processor and the plate. Since you say you can't reproduce the problem that suggests a problem with the plate.

 

[KamilT]

Dear Gordo, thank you for your advice (and for your kind words), and sorry for late reply. Yes, problem with plate is probably the only possible reason (guy from local Kodak office suggested me that maybe this can be caused due to irregular flow of developer, but he cannot explain how this can happen).
Thank you and wish you all the best in year 2016!