What is Vector-based artwork?
For spot-colour work, this is the preferred choice. File types are normally recognised by the extension .eps (not to be confused with a Photoshop .eps which is basically still a bitmap) .wmf, or .ai. Vectored images are produced using a mathematical line description (I’m trying to keep this simple!) and as such can be enlarged to any size without distortion of the image. Also, the artwork can be edited very easily to make colour changes, line thickness changes etc. etc. An Illustrator/Freehand .eps file is easily colour-separated and has the added advantage of usually being much smaller than a bitmap of the same design.
