One of our toughest jobs in direct marketing is making our copy exciting, compelling and, of all things, readable. If your customer has to work too hard to read something, you’ve missed your mark.
So insist on serif type in your body copy. You should save san serif type for headlines, subheads, or small amounts of copy. But for longer copy---paragraphs, letters, etc., serif typefaces keep the eye moving left to right. That's one reason newspapers are written in serif typefaces. So people can read them.
