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 Ghosting

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marianodejesus



Number of posts : 1
Location : Manila, Philippines
Member since : 2011-05-19

PostSubject: Ghosting   Mon Jul 18, 2011 7:20 pm

Can anyone have any idea how to solve ghosting in offset sheetfed printing...
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Sandman



Number of posts : 404
Location : Middle East
Member since : 2007-11-21

PostSubject: Re: Ghosting   Mon Jul 18, 2011 11:12 pm

Hi sir. Baka makatulong itong link: http://qualityinprint.blogspot.com/2011/02/ghosting-part-1-mechanical-ghosts.html
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presstech



Number of posts : 256
Age : 68
Location : Metro Manila
Member since : 2007-05-29

PostSubject: Re: Ghosting   Thu Jul 21, 2011 5:52 pm

Ghosting normally refers to variations in color densities specially on solid prints. This is caused by starvation of ink on the ink form rollers; because the ink is not replenished fast enough. The resulting weak patterns produced are also called starvation patterns.

The problem normally occurs when there are heavy images preceding a solid design. The images eats up ink so that the areas on the solid print after them have lower ink densities than the areas with no preceding images.

Here are some possible steps to take:

1. Check the conditions of the ink and dampening form rollers and the oscillating rollers. If the rollers are defective (hard, uneven, etc.), they may no longer be capable of supplying the proper amount of ink and ink/water balance to the plates.
2. Reduce the water feed of the dampeners. Water is the enemy of offset ink.
3. Adjust the design to avoid the problem.
4. Transfer the job to a better or bigger machine. There are some offset machines that do not have sufficient rollers to avoid this problem. Oscillating rollers are specially important in distributing ink evenly.

Hope this helps. Let us know if this is the problem you are encountering. You might be referring kasi to "wash marks", which is different.
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PostSubject: Re: Ghosting   Today at 4:36 pm

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