Exporting image for printing

Probably being real dumb here so this may seem a silly question.

I need to send of a drawing to be printed. It is an membrane overlay with 3 colours.

So far sending out for quotes I just saved as PDF. However the company I have chosen originally asked for Coral Draw format. That's I think .eps The .eps format is not listed on its own its *.ai; .eps

So basically what would you recommend as a format to offer them? BTW they have not actually said what they want yet but being preemptive and trying to learn more in advance.

Thanks

Tim

Correction Corel Draw is CDR

PDF. And if they cannot work with that then they are not a very good printer. Is this some kind of specialty printer?

Hi Gary

Thanks, that make my life easier

The printing is for graphical overlays. Always back printed on clear polycarbonate.

Tim Box