Issue exporting PDF in InDesign. GRAY background in one of the images

[DarioRojas]

I'm trying to export a PDF for printing and for some reason it shows a strange gray background on one of the images in the document. This doesn't show if I open the PDF in any software like back in InDesign or Illustrator. Here's an example of my issue

As you can see the gray background is behind the boat. The boat is originally a png image with no transparency.

[Willi Adelberger]

Did you apply drop shadow?

[DarioRojas]

There is one but it doesn't extent that far out of the boat

[chrisg11235813]

It is most likely a transparency blend spaceissue.

Your link is in a different colourspacethan your document. Change the link's colourspace to the same as your PDF output colour settings.

[Bill Silbert · Accepted solution]

I've seen this issue often when a drop shadow is cast by a contoured object such as the bow of your ship. The best chance of avoiding it is to make sure that the PDF uses a preset of High Quality Print and PDF/X-4 as the Standard. PDF/X-4 is always the best standard to use when dealing with transparency.

[Willi Adelberger]

I think it is the YDB (Yucky Discolored Box) Syndrome: https://creativepro.com/eliminating-ydb-yucky-discolored-box-syndrome/

Don't use PNG for that purpose. If you use transparency use only PDF/X-4, PSD or AI for import, no PNG.