folding carton question

[Hman56]

First time here and not real sure where to sak the but,
We need soem help with screen angles on jobs with "white down first" that have tints in the. we have found out the hard way that the whitescreen angle can NOT be the same as any of the other 4 (4 color Precess).
what asr most folding carton shops doing?

Bill Hodkinson
Beyer Graphics
Commack NY.

 

[chevalier]

Can you provide a screenshot or PDF of the artwork or similar artwork (private message if necessary)? I might be able to help. Generally when using white under-printing (down first) halftones are not utilized. It is ludicrous to expect halftone dots to align directly on top of each other as I suspect this design might be doing. The problem might be the design is not realistically printable.

Most workflows will only allow you to use 4 angles at a time. Yellow is the most likely to moire so always avoid using it unless you don't have yellow in the job.

A few quick down and dirty work arounds for problems like this that work sometimes:
Try imaging your white plate(s) at 300lpi using the Cyan, Black or Magenta angle. This tends to hide moire issues from the human eye.

Configure an output plan at your RIP to use an alternative screening set (most rips have a CMYK Classic, CMYK Modern, CMYK +7.5º) then image only the white plates with that output plan. This is a work around to being stuck with 4 angles but it doesn't always help or work.

Use stochastic screening.

 

[Hman56]

I have the PDF file, where should I send it?
our next try will be to change the LPI by 10% on the white only.

 

[chevalier]

Check your private messages I just gave you an e-mail address.