Grayscale JPG (imported) appears washed out when saved as PDF

[giardiacorp]

A grayscale JPG image (Gray color model), imported into an Illustrator document, appears washed out and partially transparent when the Illustrator document is saved as PDF.

This issue has existed in multiple versions of Illustrator. I'm new to this forum, but I try to attach an example grayscale JPG (Gray color model) as an example. You can duplicate this issue in your own Illustrator (I am on Mac) by doing the following steps:

1. Open a new document in RGB Color Mode.
2. Import grayscale JPG (Gray color model) onto the page.
3. Save document as PDF. Output will appear very washed out.

This seems to be related to transparency. If you put a black vector object on the page, drag the grayscale JPG over it, and save, then you will see the object through the JPG image in the PDF output.

[giardiacorp]

I found three different solutions to this, although none of them are perfect:

• When saving as PDF, select PDF 1.3 under "Compatibility." PDF 1.3 does not support transparency, so it somehow fixes this issue.
• Open the image file in Photoshop or some other editor, convert to RGB color mode, and re-save as JPG. Then the image can be imported into Illustrator and saved as a PDF with no issue.
• Open the image file in Photoshop or some other editor, and re-save as PNG-24. Then the image can be imported into Illustrator and saved as a PDF with no issue.

[Monika Gause]

Is that a screenshot you attached?

Can you please show us screenshots of each step?

[Ton Frederiks]

That is a strange bug.

The grayscale file behaves like a transparent object.

But only when the file is embedded.

If it is linked it behaves as expected.

[Ton Frederiks]

That seems to have started with CC 2019, 2018 and earlier work fine.

You may report it here:

https://illustrator.uservoice.com