Linked vs. Embedded images - how does it work?

[michaljanata]

I'm very basic user with Illustrator, so I would like to ask for explanation.

I have a Illustrator document with linked images, saved as Illustrator PDF, not PDF/X. It is 130 MB size.

Same document with embedded images is 560 MB.

It is clear for me until now..

But: in Acrobat both documents looks visualy same and images have same resolution (checked with Preflight), which I really don't understand why.

And second question is: What happens, if I send document with linked images to print shop, and they import Illustrator PDF into Corel Draw? What happens with images?

How does Illustrator handle linked and embedded images saved as Illustrator PDF for another processing?

Thanks for any explanation.

[Monika Gause]

In a PDF images usually are compressed with JPEG compression. In an Illustrator document they are not compressed at all. Even at 100% quality, JPEG compression saved a lot of space.

You have also probably saved that AI document with PDF compatiblity turned on (because you could open it in Acrobat), so that Illustrator document has the images embedded PLUS it has a full PDF inside. Which makes it even larger. Here's how saving works: https://www.youtube.com/watch?v=IpDh8Y7q8yE

[michaljanata]

sorry for confusing, it is my fault... I'm not working with AI document, only with PDF, but saved with Illustrator default PDF preset - that's why I call it Illustrator PDF

so if I understand correctly, PDF with linked images contains hi-res images with JPG compression for viewing and printing, but it is not editable unless I have original images, and PDF with embedded images contains uncompressed hires images and it is editable without external images

[Monika Gause]

Illustrator Default PDF will embed the AI file in the PDF. Please watch the video.