After decades of testing, we know the power of the direct mail letter. It's your "salesman in the mail". So make sure your letter actually looks like a letter. And that it’s easy to read.
That means no glossy stock. Real stationery isn't glossy, is it?
Indent your paragraphs. Real letters use indented paragraphs. Sales flyers might have flush left margins. Which are you?
Use a serif typeface for body copy. Serif typefaces are easier to read than san serif. Reserve san serif type for headlines, or very small amounts of copy.
Size matters. Go for 12 pt. type, at least. If your copy doesn't fit in 12 point, try editing it down by a few words. Odds are those few words won't be missed. And your letter is easier to read.
Can I use photographs, charts, graphs? If you must. But test first. There are some situations where a photograph or chart will work for you, but most tests suggest that illustrated letters do not pull as well as a "real" letter.
Use reasonable accenting. Notes in the margin, underlining, bold type, borders, highlighting, and other forms of accenting can highlight significant points. But don't O.D. If you do, your letter looks too contrived and does not use the accenting to direct the eye to the critical benefits you want to stress.
Break your copy up. Smaller blocks of copy are easier to read. A good rule of thumb is 25-60 characters per line. The eye needs the relief that white space provides. Rather than an eight-line paragraph, usually two four-line paragraphs will work better. You can also use subheads to breathe white space into your letter.
Sign your letter. Sales brochures don’t have a signature. Real letters do. Signatures in blue ink look more realistic.
