I regularly use Apple's Find command to search for files by their content. However, recently I tried to search for specific text in a number of PDFs of Adobe Illustrator documents. It failed to work.

I made sure the folder containing the PDFs was currently indexed. Furthermore, the text in the original Illustrator files WAS text, NOT outlines of the typography.

I'm baffled. Does anyone know if PDFs of Illustrator files aren't index-able and searchable?