Non Printing Layers Printing after Imposition

[CruzinCooler]

Hello,
I am currently adding non-printing layers to PDF's through Pitstop v24.11 for soft proofs showing media, trim, safety and perf lines. We sent files to various laserwriters and Epson proofers with the desired result of proof lines not printing. We want to use the print ready file to act as both the file to press and the file to proof to eliminate two files.
When RIPPED to Impostrip v10.8.0.5 it is apparently flatting the file and printing the "Proofing" lines on the non=printing layer sent to our digital presses for the actual printing of the book. Layers are correctly showing up in Acrobat as a Non-Printing layer.
My understanding is a non-printing layer does not print.
I'm guessing this is more of a Impostrip Ripping software thing but does anyone else have this issue.
More details to come.
Thanks for any help.

[freddyp]

Impostrip is not a rip, it is an imposition program, and that matters. The proofers you mention have rips and for a rip it is easy to honor the printing/nonprinting setting of a layer. For an imposition program that is different.

What imposition programs do is place multiple pages from multiple files onto new pages with the size of the imposed sheet, and this carries a number of implications. The PDF boxes of the placed pages, for example, have no meaning anymore. What should be the trim box of the new imposition page? That is why the pages of an imposed file usually do not have a trim box. The same is true for the output intents of the placed pages: a PDF file (up to 1.7) can only have one output intent, but what if you impose files with different output intents? Now I get to your point, the same is true of layers. Layers belong to pages, so what do you do with layers from multiple pages from multiple files? Some pages may not have layers, others have layers with the same name but different settings, etc. You should raise the issue with Ultimate, but all you can do for now is to remove the nonprinting layers from the file before imposing them.

[rhd_ole]

Hello,
I am currently adding non-printing layers to PDF's through Pitstop v24.11 for soft proofs showing media, trim, safety and perf lines. We sent files to various laserwriters and Epson proofers with the desired result of proof lines not printing. We want to use the print ready file to act as both the file to press and the file to proof to eliminate two files.
When RIPPED to Impostrip v10.8.0.5 it is apparently flatting the file and printing the "Proofing" lines on the non=printing layer sent to our digital presses for the actual printing of the book. Layers are correctly showing up in Acrobat as a Non-Printing layer.
My understanding is a non-printing layer does not print.
I'm guessing this is more of a Impostrip Ripping software thing but does anyone else have this issue.
More details to come.
Thanks for any help.

We use Impostrip completely automated for our HP PageWide, via swtich and hotfolders. In the hotfolders, there is a options in the Preferences that you can check to 'Discard Hidden and Flatten Layers'. Try that? We strip all non-needed layers prior to going Impostrip for various reason including size and unwanted results so I'm not sure if that option in preference will work or not.

Alternatively, could you do similar to what we are doing - remove all the soft-proofing layers?

[CruzinCooler]

Thank you freddyp and red_ole for your input. I will check with the Impo team and see if we have those options, for turning off layers, on the input side of Impostrip. I know we got away from hot folders a few years back in Impostrip. I believe XML submission now but now looking into JDF.