If you are using Corel 7, 8 or 9, then you should be able to export it in Adobe Illustrator format (.ai). Normally when I export a Corel file for a print shop, though, I use several different formats, allowing the shop to decide which one they like best (but ALWAYS ask for a proof). Generally I do AI (Adobe Illustrator), EPS (encapsulated postcript), PDF (Adobe portable document format), And high resolution TIFF (just in case all else fails, but it should be a last resort, since it makes all vector graphics into bitmaps, making your file size increase hugely)