PDF export is clean printed file has white around transparent images

[astoryof355226334rsd]

Hello,

I have an issue where the indesign file and the pdf file are clean and look great.  When I send to the printer some of the images have white blotches around them.  I have shared 2 different places where this is happening.  Some of the images are from the printer so they are not great but you can see the white bloches.  I am not a graphic designer and have been using the program and learning as I go.  Any help would be appreciated as I am looking to get this printed. Thanks

[rayek.elfin]

I checked your PDF file, and all affected objects are RGB transparent images that mix down into a CMYK vector background object.

To me this is obviously a RIP problem: the transparent objects have to be flattened and mixed with the background, and that's where the issues arise.

I noticed you exported a PDF/X-4 PDF.  Try exporting a PDF/X 1-A and send that to your printer. That will take care of the flattening on your side, instead of relying on the RIP on the printer's side.

(meaning: no more transparent objects in your PDF, all pre-flattened in InDesign's PDF export)

[astoryof355226334rsd]

I will do this and send it to the printer.  Thank you.

[rayek.elfin]

...it will have an impact on other parts of your design, though.

Page 90 includes semi-transparent text that mixes down into the gray background. That will also be rasterized to a bitmap, which will look downright ugly when compared next to the regular non-transparent text.

To fix this, replace all semi-transparent text with an actual fill colour/grey that matches the intended transparent effect. This MUST be done. Avoid transparency for text if you can and replace with opaque colour fills instead.

[rayek.elfin]

So basically check the pdf output first for unintended rasterized text/vector objects or parts, and then fix those in InDesign. Then create a new PDF, check again, and if satisfactory: send to your printer for a proof.

[rob day]

This MUST be done. Avoid transparency for text if you can and replace with opaque colour fills instead.

The printer should be able to handle flattening and transparency effects—and they have apparently done it in the past without any problems in earlier versions.

[rayek.elfin]

Correct, but in this case a parameter has changed. At the very least a conversation with the printer is required to identify where things go awry.

Mixing in 1% of CMY into the backgrounds might resolve the issue if the raster resolution is the culprit (I think - I am not a printer).

I also have to wonder about the printer's knowledge if they haven't been able to figure this out for their client, btw.

[rob day]

Mixing in 1% of CMY into the backgrounds might resolve the issue if the raster resolution is the culprit.

Even with a raster vs. vector issue there shouldn’t be random artifacts showing—@astoryof355226334rsd print samples look like something you would get with severe JPEG compression. I printed one of the pages on my RIP driven inkjet printer and there is no sign of the problem.

[rayek.elfin]

I thought the same initially, but the strokes of the drawing remain sharp looking, which is inconsistent with severe JPG compression. The strokes that close to the artefacts should be affected by that.

I remain convinced that the transparency in the printer's RIP is causing the issue. One RIP is not the same as another. It may be a setting on the printer's side as well.

Delivering a PDF/X 1a file to the printer will be enlightening in term of results.

[astoryof355226334rsd]

Thank you.  this is very helpfull.

[astoryof355226334rsd]

Yes, the printer says it's my problem.  I am not a graphic designer and have been fumbling through this and learning along the way.  All of this is very helpful as I learn the language that you are speaking.  

[rob day]

Yes, the printer says it's my problem.

Is this an online printer?

[astoryof355226334rsd]

No, it's a local printer.  They are closed on the weekend so I have to have a file ready for them for monday.

[rayek.elfin]

That's too easy an answer, if you'd ask me. They could be more forthcoming about potential issues and answers/fixing things.

But my experience is that many printers just don't possess the printing knowledge anymore because of a shortage of people who know their printing stuff.

[rayek.elfin]

What seems to happen (based on the printed result samples) is that the printers' RIP converts the areas where the transparency mixes down into tiny bitmap squares/rectangles. But the print raster of the background isn't matched because the image is printed at 300DPI while the vector object in the background is (seemingly) printed with pure black ink and a higher raster resolution (at the print device highest output resolution).

But to be sure I would have to examine the original print with a printer's magnifier glass. Hopefully this won't be a problem with the PDF/X 1-a version, since there will still be parts vector and parts bitmap with the same background colour - just larger areas.

As always: you can't know unless you print a good proof.

[reproo2773183]

Looks to me like the RIP at the printer is treating 0/0/0/60k as a spot colour (DeviceN) so when it tries to raster the transparency it thinks it can overprint, but it doesn't, instead it punches out the k channel.

They should be able to fix this by first converting all to cmyk and then try to raster the transparency, and not try to do both at the same time.

[astoryof355226334rsd]

I am going to send this information to the printer.  I have sent them the indesign file as well packaged it for them and they continue to have this problem.  I am not a graphic designer and have no idea how to fix this.

[astoryof355226334rsd]

FYI - I am still working on this problem.  Thanks for all the advise I have passed it on to a graphic designer.

[notannhavoc]

Hi all, So I'm the graphic designer who has been wrestling withthis issue for  several days now.  I may be on to something but don't quite understand why.  yes, it is an issue of RGB to CMYK conversion and transparency flattenign. So if I export from ID to pdf/1xa I get bad pixellation and  the same bad ghosting/halo when  actually printed. However, when I export using a preset supplied by an online printer [Createspace = now Amazon Kindle KDP] which is based on  pdf/x-1a but do not input pdf/x-1a into the standard - it creates a much larger file with no ghosting/halo. Transparency flattenign is set to high resolution in Advanced. To check the results, I've been examining the  resultign pdf at 800% . When the same file is exported from ID with pdf/x-1a selected as a standard - the file size is much smalller and I can see  artifacts which are the problem.  Curioser and curioser, when I convert the file in Acrobat to x-1a using  the preflight, artifacts are introduced. So it seems that pdf/x-1a is itself the problem. Why is this?  I wish I could tell from the pdf file how it was generated. I'm using Acrobat's preflight profiles to check for CMYK and transparency flattening  but can find no info as to the settigns used to generate the pdf. So  why does pdf/x-1a introduce the very artifacts it is  supposed to eliminate? How to tell the settings used for generating pdf?good result -no artifactsID preset used for good resultwith artifacts- ID preset as pdf/x-1aID preset for x-1aconvertd to x-1a with acrobat w artfctscolor conversion settingsfrom ID w good preset but color conversion 

[rob day]

So why does pdf/x-1a introduce the very artifacts it is supposed to eliminate? How to tell the settings used for generating pdf?

Hi @notannhavoc , I’m seeing the same compression artifacts in both the PDFs you shared. Can you share the InDesign page and assets?

You can choose to turn off JPEG compression with a PDF/X-1a Standard export:

Also from AcrobatPro you can use its preflight to check whether a PDF was exported as X-1a:

[notannhavoc]

hi - thank you  for this. I'm attaching   some of the files used on this page- I've only added the image of the  people in suits at top right since tha t is what we are examining . Yes - I suppose it is the compression that is making the difference. You say the 2 pdf  files previously  uploaded are the same - but they are not - one has  slight squiggly halos around the black lines - exactly what we see in the printed version - the  other file [june 29 - createspace-convert colors.pdf] does not have these. I am not concerned about the white hairlines as I know these will not print. I am familiar with Acrobat preflight adn that is what I've been using to  ensure all colors are CMYK and transparency is  flattened. However, isn't there some setting  somewhere that allows me to see what  parameters/choices/settigns were used to create the pdf file it is analyzing?

[notannhavoc]

Ah - I see that I can at least determine what pdf standard it is by running the check

I will see if  I get the same results with  exportign as pdf/x-1a with  compression turned off

[notannhavoc]

so I've exported as pdf/x-1a a with compression none - however - it STILL has the  ghosting/halo [at edges of anti-aliasing] unlike  when exported as pdf/x-4 from the  "good" preset. see image - the right is  pdf/x-1a - the left image is much sharper and has no halo/ghosts. [hm - when looking at it at  1200% I do see some ghosting but not as much as  on the pdf/x-1a version].  So can we infer that pdf/x-4 is the way to go? I can ensure that all objects are CMYK and transparency is flattened.

[rob day]

There are a few things to consider with the files you shared:

Look at the Effective Resolution and scaling of the "line" art. In the .png example you provided, the Actual Res is 72 PPI, the Effective (or output) res is 6,579 PPI, and the Scale is 1.1%. So if you set the Compression Downsampling even to the relatively high 600 PPI, the line weight scales to 10% of the original—the anti-aliasing zoomed in at a high magnification is going to be obvious with a line that thin.

Also, the PNG is RGB, so the line is going to output as 4-color while the background will output as black only. The document also has no CMYK profile assigned, so the CMYK output values will be depend on your Color Settings Working CMYK space, and could change every time the file is exported. I think you would be better of with Grayscale .PSDs. In that case the lines and background gray would export as Black only.

Here I’m exporting with the downsample set to 1000PPI

The PDF viewed at 3200%(!)

With Downsampling turned off :

Which might get to the problem at the printer. Many printers will not let resolutions higher than the standard 300ppi output without a further downsample. So the printer may be downsampling your PDF from the 600PPI I’m seeing in your sample, to 300ppi, which might accentuate the PDF’s JPEG artifacts (which is different than line anti-aliasing.

[notannhavoc]

yes - I think you've hit the nail on the head - the problem is when the printer downsamples to  300 . So now my problem is how to fix this?  there are thousands of  discrete objects [all done at 72 dpi but at huge size [8000 x 8000 pixels] I've resampled some but  it will be a HUGE job to resample them all. and when I do resample - the layout changes and that causes no end of problems. I can make the output intent Photoshop CMYK 4 or 5. I was hoping there woudl be some magic combinationof settings so I don't have to go in and  resample each individual object?

[rob day]

I would turn off the JPEG compression and ask the printer if they can output without any downsampling. Line art typically needs at least 1000ppi