Artwork changing when saving file

[VLS15]

Hello, I'm having an issue where some of the artwork in my Illustrator file changes when I save it even though I didn't make those changes.

I open a PDF file in Illustrator (the PDF was originally created in Illustrator) and "save as" to a PDF with a different file name. When I do this, some of the strokes change even though I didn't make those changes. 

Any ideas how this can be fixed? Is this a bug? 

Thanks for your help.

[Monika Gause]

Please tell us details of exactly what changes how. Screenshots help understand.

Also: did the PDF have an embedded AI file or did you import the PDF?

[VLS15]

 

Thanks for your response. Attached are a couple of screenshots. You can see that the red curves are different. This happened just by saving the PDF in Illustrator using "Save As".

I don't believe the PDF had an embedded AI file. I just opened the PDF using Illustrator. 

[Monika Gause]

How does the PDF look inside the Layers panel? Are there more than one layer?

Are there clipping masks (lot of them)?

How does the PDF look when you open it in Acrobat?

[Met1]

I can't tell the scale from this but are you zooming in very close to a small pair of pants? If so are you viewing one with CPU preview and the other with GPU preview?

[marliton]

Hi.

1. Check in the Appearance panel if the path has an Effect applied.
2. Although it is not common nowadays, some paths could be problematic if they were created incorrectly. Try simplifying the path: https://helpx.adobe.com/illustrator/using/simplify_paths.html