Illustrator opens a .pdf file with seemingly hidden pages, how is that possible?

[jimhoyle]

I createad a .pdf file in Illustrator. Originally that is an .ai file with multiple artboards. The pdf was created as Save as, PDF, Range 3 (artboard 3). When I open the saved .pdf in Photoshop, Acrobat Pro or Chrome, indeed I get the correct 1 page as intended. However, if I open this exact same .pdf in Illustrator, now suddenly the original content with all multiple artboards appear.

I do not understand how this is possible. I tried to save both [x] Preserve Illustrator Editing Capabilities on and off, that didn't have any effect on the number of artboards.

Can someone explain what's going on? Acrobat's Document Properties clearly shows Number of Pages 1. But still Illustrator opens all the pages (artboards), not just one. When the .pdf is open in Illustrator, I can clearly see it's the same expectedly 1-page file, I have not mistakenly opened a wrong file.

[Doug A Roberts]

If I save a 3-artboard file with preserve Illustrator editing capabilities turned off and 1 artboard selected, it reopens as I would expect, with only one artboard.

Please list the exact steps you're taking if you see a different outcome.

With Illustrator editing capabilities turned on, I would expect to see the original three artboards as Illustrator is opening the AI file, not the PDF side.

[Monika Gause · Accepted solution]

As Doug wrote.

This is what happens when Illustrator saves files: https://www.youtube.com/watch?v=IpDh8Y7q8yE

[jimhoyle]

Ok, now I found surprising details about this. 

According to my tests, PDF is indeed a format that can hide pages even from Acrobat. Then hidden pages are not visible to Acrobat, Photoshop, Chrome (those I tried). But Illustrator opens them. Indeed, [ ] Preserve Illustrator editing capabilities is the setting that removes those hidden pages from the PDF file. So when saving as RANGE (and for example one artboard only out of many), but with [x] Preserve, then somewhat illogically it actually saves all artboards, just leaves the range visible for Acrobat etc. I don't think preserving editing should override the range setting.

Another thing is, I'm not sure if I got it working reliably now, but I did also use Actions for saving. And that is also very confusing, because when double clicking an Save a copy (PDF) item in the Action, it doesn't show the action's current status. It shows something else, so it may seem [ ] Preserve when actually the action has [x] Preserve. That may be the reason why I thought Preserve was off.

[Doug A Roberts · Accepted solution]

Illustrator actually saves two files when saving a PDF with AI editing on (or an AI file with PDF compatibility), both wrapped in a PDF container. Illustrator will open the AI side of the file (with all artboards), Acrobat will open the PDF.

This info is all in the video Monika posted.