Product

Platform

Operating system

Error

Symptoms

Sometimes, a customer finds the Prinergy-supplied screensets to be inadequate for their situation.

Cause

Solution

Through the use of a configuration file, you can now add your own screen systems with whatever angle combinations you wish. The one condition is that of the 4 angles, 3 of them must be pairwise 30 degrees separated.* The geometry solver will figure out which ones are which and generate optimal moiré free geometries for the 3 pairwise 30 degree separated angles. The other angle ("free angle") will have its LPI stretched by 14% to minimize moiré.

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- Go to AraxiHome\AdobeExtreme\bin\CreoScreens

- Create folder "Config"

- Create file "Creo_SCDV.cfg"

(Note that the screening systems in the file will be added to (but will not override) the existing screening systems.)

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Format of the file:

---------

<Screen System Name>, <float> <float> <float> <float>

#

---------

Details:

- '#' can be used to add comments.

- File must include a trailing "#" after Screen System Name lines

- Blank lines are fine.

- Whitespace preceding <Screen System Name> is fine.

- Whitespace in a screen system name is fine.

- The floats represent the CMYK angles (in that order).

- <Screen System Name> MUST contain "Creosettes" at the beginning of the string. e.g. "Creosettes Mysystem blahblahblah-a2341-h32".

- You should take care not to make the <Screen System Name> name too long.

- Ensure that there are no negative values in the screen angles.

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For example, a Creo_SCDV.cfg could look like:

---------

Creosettes - Special Screen, 75 45 83 15

#

---------

After you restart the RIPs, "Creosettes - Special Screen" will appear as a selectable screen system in the process plan editor.

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You will have to repeat these steps for all renderstations.

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* Note: If Prinergy reports "error while sorting screen angles!", the angles are probably not pairwise 30 degrees separated.

For example, For the set: 82 37 97 142

Take the first-quadrant value for each angle (i.e. subtract 90 until you have a number between 0 and 90, for each angle) and sort them into ascending order (i.e. clockwise from zero at 12 o'clock position).

Now you have: 7 37 52 82

And the separation between angles (or "angle differences") is 7 (+30) 37 (+15) 52 (+30) 82 (+15) (97), therefore it won't work.

or more simply, 30 15 30 15. BTW, as a check, these numbers must add up to 90, or you did something wrong.

In order for three of the angles to be "pairwise 30 degrees separated" the sequence of angle differences has to be 30-30-15-15 (or 30-15-15-30, or 15-15-30-30, etc.) Note that the fourth angle can really be anything you want

One way to quickly check whether a set will work is to check the last digit of each angle. If there aren't three angles ending with the same number, it won't work.

Permanent fix:

See also

Keywords

output, screening

Technical contact(s)

James Bredenhof; Chris Joughin

Submitted by

James Bredenhof

Date submitted

06 Nov 2002