Dark boxes around a poligon with a line and shadow containing images in printed file

[Verdegiallastro]

Hi, I have a little big problem,

I did a graphic panel but the printing result came out like the attached image shows, dark rectangles behind the pictures which are placed inside a white line with shadow (effects in indesign).

The printer said that the "error is mine because I use Indesign and not Illustrator" and because their lack of Indesign knowledge they don't know what is wrong in the PDF, which looks perfect to me: 
https://shared-assets.adobe.com/link/cc6aab58-1b25-48d5-65d3-524ffb575edf

In this link you can find the Indesign file and the 4 pictures used (changed to low-res):

https://shared-assets.adobe.com/link/3241b186-1336-41ec-4daa-55d318bf6bcd

I have tried reading similar topics but unfortunately I cannot find the problem

I need urgently a help to resend the files in the next 12 hours so I would be gratefull for the support

Best regards
Carlos

[Peter Spier]

What settings did you use to export your PDF?

I strongly suspect the printer tried to open your PDF and print using Illustrator. Illustrator is not a general purpose PDF reader/editor and should be used to open only those PDFs actually created in Illustrator.

Can you find another printer who actually knows how to print PDFs produced from InDesign?

Is this perhaps screen-printed and the printer actually needs native Illustrator files for some reason (I've seen this request some years ago, but haven't had a screen-print project in more than 10 years). If there is something about the printing process that requires Ilustrator files, and the printer specified this, and you gave them PDFs from InDesign instead, then the error is indeed yours.

[Verdegiallastro]

Hi Peter,
Thank you for replying. Unfortunately I can't change the printer but illustrator was not required, they are just claming that only Indesign causes this problem. 
Attached you can find the presets used. 

[Peter Spier]

Your PDF should have exported with live transparency (PDF/X-4), but what your print is showing looks like it might be this: https://creativepro.com/eliminating-ydb-yucky-discolored-box-syndrome/

[Verdegiallastro · Accepted solution]

Unfortunately I read this but I don't have spot colors and think I have the right flattening presets already with the overprint checkbox correct. I have tried in different printers with the PDF file and the result is good, just not with this large size printer  😞

[Peter Spier]

YDB is not a spot color problem, it's a raster/vector ripping problem, and the suggested cure was to rasterize everything.

[Peter Spier]

Exporting PDF/X-4 doesn't flatten anything, so simulate overprint is moot.

Do you know what printing method is being used here?

[Peter Spier]

I see you've apparently used the Page Tool to resize the layout. While I don't think this should have an effect on the output, for a job like this it makes me nervous for no rational reason -- I just don't llike the Page Tool -- and I would probably make a new file at the correct size and copy the content into it.

You've embedded the images, which is unnecessary and makes your file much larger on disk (in this case about 500 mb), increasing the chances for file corruption. Linked files are just fine.

Two of your images have very low effective resolutions and show an awful lot of artifacting. This may not really be a problem, depending on the viewing distance. for your images with effective resolution of 13 ppi your viewers need to be more than 30 feet away.

[Verdegiallastro]

Hi Peter
Thanks again. No, I didn't resize the layout and I agree with you, I don't like the page tool. You're right, at first I embedded the files by mistake, when I realized the large size I linked the photos again. The images are very low quality for example purposes only, but the problem seems to be a wrong color convertion of the shadows from my CMYK PDF file to a RGB driver printer. I wrote below my suspicions, replying to Scott Falkner

[Peter Spier · Accepted solution]

It would really help to get some info from the printer on exactly waht they did to produce that print. I'm still suspicious that it went through Illustrator and also that their RIP is not handling the shadows correctly.

[Verdegiallastro]

Yes, your suspicions are correct for me, I opened the PDF with Illustrator and there are mask lines created by Illustrator containing the hexagons, covering the same perimeter as the dark boxes. Now I'm trying to "hunt" the printer. Thank you.

[Peter Spier · Accepted solution]

Ultimately you may have to rebuild this in Illustrator to get this printer to give you good output.

[Brad @ Roaring Mouse · Accepted solution]

My two cents (as a prepress person)

Your file is just fine, assuming this is the one you sent them. (with caveats as I will list below).

Testing to both of my printers, one CMYK, one RGB, it rendered perfectly.

That being said, To get you going right now, what I would do is to eliminate the middle man (i.e. whatever shenanigans they are doing to f*ck it up, and YES they are at fault) and just render the entire PDF into an image file in PhotoShop. Normally I would say do it as CMYK since you're there already, but if they are sending it as RGB, might as well render it as RGB (sRGB). The size of your panel doesn't need much in resolution so I would open it in PS at 100 ppi. Save either as a TIFF. or JPEG with highest quality. If they won't accept a TIF or JPG file directly, create a quick Illustrator file and place that image, and then send that off to them.

Back to the PDF.

Your PDF export settings are execessive. For a display panel, there is certain no need to downsample to 600 ppi.  75-100 is more than fine for a display panel (just make sure = maximum quality compression)... even 50 wouldn't be seen by anyone even remotely close to it.

Colour Conversion: Normally the recommendation these days is No Conversion, but it doesn't soound like these yahoos would know what to do with that anyway, soooooo.. what may have helped here is converting EVERYTHING to the destination space. i.e. don't use Preserve Numbers. Your file was already assigned the FOGRA document space, so even your CMYK colours would remain the same into the PDF while the rest is being converted. This keeps everythng in the same apples-apples world.

[Verdegiallastro]

Hello Brad,

I really appreciate your time and feedback and I will study and pursue the more technical suggestion you mentioned for the future. Unfortunately, the contact between me and the printer insists that it is a file problem. Fortunately, the client is happy with the overall result. So, your "eliminate the middle man" suggestion will still be my favorite
😄 😄 😄

Many thanks!

[Scott Falkner · Accepted solution]

You need to make the drop shadow a different layer then import the image of the grips twice, once without the drop shadow, once with, and set the drop shadow to Multiply. This must be done within InDesign.

I used a quick path to mask the grips and put them on a separate layer.

https://www.dropbox.com/s/hy9f0k73fw92wlb/Nucore_Wall2%20Folder.zip?dl=0

[Verdegiallastro]

Hi Scott,
I appreciate your time, comment and example. Unfortunately, the problem is not with the grips, the problem is with the "arrows/hexagons" with their lines and shadows. I went through different magazines that I sent the same PDF print file too, and the result is good and correct. Reading more, and looking at some new photos I got (attached 1), I suspect that the problem could be, the printer is printing in RGB, making a wrong conversion from my CMYK file, which could explain for example also the accent on the reds and the overall colors a little darker than should be.

Maybe you/someone has the same suspicion?