Skip to main content
T
tom_morse1
Participant
June 12, 2017
Question

Preflight overprint AND blend mode

  • June 12, 2017
  • 3 replies
  • 4494 views

Hi all,

Got a head scratcher here... I'd like a preflight to flag if an element has Overprint AND a Multiply applied.

An example would be: A greyscale tif, coloured with black, exported as a 1.4 PDF, and a preflight which provides these results

conatiner with:

  • Overprint On + Multiply On = Fail
  • Overprint Off + Multiply Off = Pass
  • Overprint Off + Multiply On = Pass
  • Overprint On + Multiply Off = Pass

Here are 2 examples of the Graphic state properties, of different options. I can't see any difference, but think I may be looking in the wrong place?

It sounds like it should be super simple! But for the life of me I can't get it...

Any help would be greatly appreciated!

Tom

This topic has been closed for replies.

3 replies

abailescollins
abailescollins
Participating Frequently
April 30, 2018

Seems pretty straightforward in PitStop actually..

Select if fill overprint is on

Select by blend mode (configure for multiply)

AND

Log Selection (write a custom message)

If you want to check for the possibliity of a overprint stroke as well that's also possible, but would need a few extra actions.

dario.
dario.
Known Participant
April 27, 2018

Can I ask you why you need this?
...I'm having a similar issue!

Stephen Marsh
Community Expert
Stephen MarshCommunity Expert
Community Expert
April 27, 2018

Does your RIP/DFE choke or produce incorrect results if both overprinting and multiply blend mode are used?

T
Test Screen Name
Legend
May 27, 2019

I don't think you can have overprint on an object that gets its colour from a calculated blend mode. What colour do you want to overprint? The colour before it is blended (which has changed efter blending) or the color after (which depends on your CMM settings and is not fixed when overprint is calculated)?

Will it work with overprint and other blend modes? (I guess "Compatible" means those that are Compatible with overprint? Would be nice with a better help text on this from Acrobat)


Lukas, I once spent a lot of time reading the PDF specification about transparency. Weeks, perhaps months. Anyway, overprint is treated as applying to the channels BEFORE applying the regular blend mode; it isn't further preserved. The specification is full of stuff like "If the current blend mode when CompatibleOverprint is invoked is any mode other than Normal, the object being painted shall be implicitly treated as if it were defined in a non-isolated, non-knockout transparency group and painted using the CompatibleOverprint blend mode. The group’s results shall then be painted using the current blend mode in the graphics state.", this goes on for pages.

T
Test Screen Name
Legend
June 13, 2017

Look at overprint for stroke and overprint for fill, independent properties. 

T
tom_morse1Author
Participant
June 13, 2017

Thanks for the reply, but it's not that.

The graphic state properties shown in my screen grab are created from a single tif in Indesign set to overprint AND multiply. It's been split into 3 parts.

  • The image
  • The image with overprint
  • The image with multiply

I need to be able to check these properties as if the image was one element.

I've attached a .zip here which contains an Indesign file, a tif, and 4 PDFs. The PDFs are named with the result I would like a preflight to find.

https://drive.google.com/file/d/0B6tR5XpHS_KwSkExbzNjR0l0Yk0/view?usp=sharing​

Any help is appreciated!

Cheers

Tom

Stephen Marsh
Community Expert
Stephen MarshCommunity Expert
Community Expert
June 17, 2017

This may be possible in Enfocus PitStop Pro 2017, which has a new “geomapper” feature that can look at the interaction of stacked objects as if they were one object… However this is a new feature which I have not had much time to play with and it may be limited at this time in what it can check.

Terms & ConditionsAccessibility statement
Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices