Trouble PDF

[Slappy]

This one caused a little bit of a stir today. The screened areas behind the text are supposed to be the same light green, but on one set of 4 pages only - it's decidedly NOT the same. In the InDesign doc, it was a PMS swatch, had been brought in piggy back from an AI logo, the prep person converted it to 4c (I believe through Pitstop) and I can't for the life of me figure out why it RIPs differently than the other pages. Here are the 2 pages, as they were imposed if anybody wants to poke around.

(Spoiler alert: I have a suspicion already but want an unbiased confirmation.)

[abc]

That green is not CMYK, it's Lab. Same value on both pages, but definitely not CMYK!

[Joe]

Yep...both show as Lab. Not sure why they RIP differently since they both show the same Lab values.

[abc]

Indeed, and I can't see anything else that would cause them to be different.
Output intent, transparency, ICC profile etc. They look to be the same.
Were both pages on the same imposed sheet, or on different ones?
Just wondering if they were handled or ripped differently?

[abc]

'but on one set of 4 pages only'
Would suggest these 4 were processed differently (if imposed 4 to view)?

[Joe]

If I manually convert one to CMYK with Pitstop the difference in the two looks like this. the converted one, while different, doesn't go completely gray like your example shows. Something had to be done differently to one of them.

[Slappy]

Correct, all 4 were on one side of an impo. And also correct, when the other person converted it to CMYK, that PMS got left in LAB, I suspect because the color space of the swatch in InDesign was LAB. I can't explain to anybody why the RIP processed those signatures differently however.

Think I need to look at the Pitstop Action, maybe it's leaving specific builds alone?

Oh, and it printed bound & delivered too. :embarrassed:

[Joe]

I'll run those two files through Prinergy when I get to work but at the moment I am betting they will both look the same on the other side.

[Slappy]

Thanks! If you're feeling adventurous, I can isolate some of those pages & package the original InDesign file from the client too.

When you said you "manually convert one to CMYK with Pitstop" I'm guessing it was with the "Convert to CMYK (using Preferences)
 - how are your Prefs set?

[Joe]

Thanks! If you're feeling adventurous, I can isolate some of those pages & package the original InDesign file from the client too.

When you said you "manually convert one to CMYK with Pitstop" I'm guessing it was with the "Convert to CMYK (using Preferences)
 - how are your Prefs set?

Yes with Pitstop Inspector instead of Global Change or an Action. My color settings are always 'off' by default.

[Joe]

OK I ran them through Prinergy. They both come out the same all the way to plate files. Neither PDF has any spot colors in it but the values of those backgrounds is in Lab values. Prinergy converts the Lab values to CMYK values. I'm not sure how one creates a PDF out of Indy and keeps Lab Values. If you can send me the Indy documents I will take a look though.

[abc]

Well I think that probably explains it, one side in CMYK, second side in Lab that would then be separated by the rip = different results

[Slappy]

Except - ALL the pages with that particular build have the same LAB values. 

I can send you the working files too, and the full imposed PDF if you're curious.

[Joe]

In Prinergy both PDF's were converted to CMYK during normalizing and the plate files have the same values. Converting the Lab values to CMYK in Pitstop with color management turned off produced the same values that Prinergy converted them too. So far I can't make them appear different at plate stage.

[Farabomb]

I ran it through and they converted the same. The only thing that's weird is a deviceN element over the top but it's present on both pages. I don't understand how after running it through a refine that should convert everything to 4c how a deviceN element remains.

Visually though it doesn't matter as they both look the same and have the same color values.