"Mooring Bars" What are they and how do you use them?

[P_Crosby]

Greetings All,

Typically on web presses when the job content does not extend to the edges of the roll bars are added to the outer edges to help maintain ink and water balance. I've heard them called mooring bars, mourning bars and take off bars.
Do you use them?
How do you use them?
What do you call them?
How do they work?
What is the impact on CIP3 ink key control systems?

Phil Crosby - Senior Trainer - Agfa Graphics North America

[Dan Roll]

A certain amount of image area on the plate outside of the web width (this can be bars, screen, patterns, solids, not everyone agrees on how much image coverage is optimal) keeps the ink from drying on the blankets outside of the web area and prevents water from building up in the ink train on the edges. There are many web printers who do not use this trick, but I think they work very well.
The impact on a CIP3 ink key control system I will leave to those who might have one, but I suspect there is little if any negative effect and more likely some positive effect.

[Cornishpastythighs]

If you put mourning bands on the edge of your plates the CIP3 will see it as image and will apply ink key openings accordingly, you would have to manually bring those settings down as you dont want to actually feed new ink to image area if you are not removing it with web. If you are running closed loop colour/ink control those inks keys inline with the mourning bands will have to be disabled so that they get ignored by the inkinging system. We used 40% screened mourning bands but some will have other opinions on the screen value or effectiveness of them. Giving the ink/water something to do on the outside of the blanket seemed to save blanket delamination to an extent. I agree with Dan.

[Alois Senefelder]

Hello fellow Lithographers,

PDF's Hopefully of interest --