I found an answern What plausible is that somewhere along the way from the scanning device to the PDF-creation software italic both of which can perform OCR (optical character recognition) these partial converting it to a PDF optimizing that PDF and then opening it up in Illustrator does in fact create layers similar to what is seen in the birth certificate PDF. You can try it yourself at home. n n UPDATE II For those of you who still aren convinced here italic a one-page PDF that I just scanned and optimized so you can see for yourself that an optimized PDF shows up in Illustrator as layers. (I didn spend hours getting the settings right.) n-Nathan Goulding National Review