Transparency problems with PDF Export

[laura@campstompingground.]

When exporting a PDF, I am finding that some of my images are exporting at full transparency when I have pulled the image itself down to about 80% transparency.

I have other images imported the exact same way from the exact same Ai file that are pulled down to 60% transparency that look fine once the file is a PDF, so it's not like it's totally incapable of doing it. I am wondering if 80% is just not enough of a difference unless I super update the quality.

Wondering if I should just find out whatever color it 'looks' like when it's transparent and just make my graphs that color. 

Screenshots of indesign vs. the PDF are attached.

[laura@campstompingground.]

Updated to say - it does show as transparent in Adobe Acrobat, it was just Preview giving me a hard time.

[BobLevine]

Then there's nothing to fix. Preview (along with many 3rd party PDF readers) is garbage for anything but plain vanilla PDFs.

[rob day]

it was just Preview giving me a hard time.

Preview is a fully color managed application, so if the PDF color is not profiled, Preview would be assigning its own default profiles, which might be different than your InDesign profile assignments. So here Preview isn’t having any problems with the transparency, but in order to get a color match to InDesign I have to include the color profiles:

[rob day]

Hi laura@campstompingground. , Looks more like a color profile issue. What are your Export>Output Settings? If the exported color did not have profiles embedded Acrobat and Preview might display the color differently.