The industry standard in electronic files for printing has changed much over the years and
seems to have settled on PDF.
Because the PDF format is universal across all platforms, it makes an ideal file format from
which to print.
Its printing content is Postscript and as such it is identical to the print content of an eps file
(used extensively before PDF won the format wars). However its file size is much smaller
than eps, so it’s also a good format for transmitting electronically, either by email or FTP.
The PDF was invented by Adobe, who are also responsible for the eps file format.
PDFs are exceptionally good at calibrating ink usage.
Make sure your PDF is cmyk! (cyan magenta yellow black).
RGB (red green blue) PDFs won’t print correctly.