Saving files in Illustrator

Question

Hello,
Rookie question: I have had someone doing work for me in Illustrator (CS5) and she has saved all files as .pdf. There is not a single .ai file on the machine. She says there is no reason to save as .ai because Illustrator will allow us to open and edit the .pdf files anyway.
Is this correct?
Also, can a file be created in Illustrator and ONLY saved as pdf (I would think it is necess to save the .ai first and then create pdf later)?
Thank you for your help,
Chris

Answer 1

When you save an Illustrator file in AI format with the option Create PDF Compatible File turned on (default), two entire versions of the artwork are written into the file: one as native AI content, the other as "dumbed down" PDF content, "cordoned off" as if in a "black box" for use by other programs which cannot open the native AI content. The file is given a .ai extension, and should show an Illustrator icon in the OS. When you try to open that file with Acrobat, it is the dumbed-down Acrobat stuff that opens, not the native Illustrator stuff. Similarly (and often not realized), when you import that file into InDesign, it is the dumbed-down PDF content that is actually imported, not the native AI stuff. InDesign cannot import an AI file if the PDF version of the content is not included.
Inversely, when you save an Illustrator file in PDF format with the option Preserve Illustrator Editing Capabilities turned on (again default), two entire versions of the artwork are written into the file: one as "dumbed down" PDF content; the other as native AI content, "cordoned off" in a "black box" for use by Illustrator. So this just flops the whole thing. The file is given a .pdf extension, and should show a PDF icon in the OS. But when you open that file with Illustrator, Illustrator checks for the Illustrator-native content and opens that.
Back when this nonsense was implemented, it allowed Adobe's marketing to claim that "PDF is now Illustrator's native format."
Many designers, seemingly proud of their esoteric knowledge that this confusing crap is going on, seem to think it somehow "clever" to therefore save every thing as a PDF, because "After all, it contains the AI-native content, too." Doing so is bad practice, because as you've discovered it just creates confusion for downstream users who don't understand why they get properly editable content when they open one "PDF" with Illustrator, and why they get dumbed-down garbage when they open another PDF.
My advice:
If the file is intended for later editing in Illustrator and/or for archiving, don't play games with downstream users; just save it as dang Illustrator file. Yeah, if you're not worried about needlessly bloated file size, go ahead and leave the PDF compatibility option on.
If the file is considered finished, and is intended for delivery as a PDF, just save it as a PDF. If you don't intend for the recipient to edit it in Illustrator, turn off the Preserve Illustrator Editing Capabilities option and thereby significantly reduce the file size. Yeah, if you just don't trust yourself to deliver a properly print- or press-ready PDF and consider allowing some unknown dweeb with an unknown expertise level at the printing house to muck around with your file at the last minute some kind of "safety net"—go ahead and leave on the Illustrator Editabilty option if it makes you feel better.
My practice is to act like I always did before this silly smoke-and-mirrors stuff was implemented. I think and work in terms of "working files" and "delivery files". I save the working file in AI format, and leave the silly embedded PDF option on jus because it's default, unless I'm sending it to someone and want to minimize file size. When I save as PDF, I turn off the Illustrator Editabilty option because I don't intend for someone to edit it in Illustrator. (If I did, I would...duh...send an AI file.)
In other words, I basically pretend that the smoke-and-mirrors doesn't exist, and I don't try to be "clever" about it. I save what I think of as a native AI file in .ai format. I save what I intend to be a PDF file in .pdf format.
For more esoteric fun & games, we can later talk about the equally nonsensical idea that PNG is the "native format" of Fireworks.
JET