We have an issue on one of our machines that suddenly for no reason when we make press ready PDF's and turn on Overprint preview its not display correctly and showing the black (set to overprint) is knocking out, however when we run seperations to our printer they are overprinting?
The odd thing is that when we take the same PDF to any other of our machines and look at it in Acrobat it displays as it should and is knocking out.
This appears to be an issue with the acrobat Pro 6.0.2 on one machine not displaying the file correctly as it prints out okay and looks okay on other machines.
I have searched the internet and cannot find a similar problem reported.
Any ideas?
I am not sure that you black has overprint "on" in that PDF - it may not have overprint on, BUT the reason your separations then overprint is that the separation engine/RIP has black SET TO OVERPRINT regardless of the PDF setting. Many Agfa RIPS (for example) even allow the user to set WHEN a black will overprint - for example, you can set what point size black will overprint and when it begins to Knock-out (and then trap) - 36 point i where many set this.
Overprint is a setting that can be ignored, replaced, applied (using FLATTEN) and honored in a RIP, so you need to be aware of that - Enfocus PitStop Pro offers tools to view if an object has overprint "on" or "off" and allows the user to change the setting.
hope this helps and gives you some clues !
Michael Jahn
Application Support Specialist
Compose Systems Inc, USA.
4740 Northgate Blvd. Suite 100
Sacramento, CA 95834
Tel: (916) 920-3838 ext 102
Fax: (916) 923-6776
Email: michaelejahn [at] composeusa [dot] com
Web: www.composeusa.com