Read the following passages and choose the best answer for each question. (1-6)
    Behind every good letterhead is a solid creative idea. And it’s that idea that makes one letterhead much more impressive than one which is based on little or no thought.
    A business person with no training in art tends to think that a great logo automatically makes a great letterhead. This is not the case. A great logo incorporated in a good letterhead concept does make for a great letterhead. Even without a logo, an eye for type and design can be sufficient to make a stand-out letterhead.
    When designing a letterhead, avoid following the now-that-I-have-your-attention model. You don’t have to go to great lengths to make your letterheads stand out. People read only one letter at a time, and a letterhead doesn’t have to fight for attention the way a small ad must when it’s in a magazine dominated by big advertisements.
    Those who seek attention with their letterheads often go for excessive use of vivid colors. That’s tacky. The result can be devastating to the image of a company. Color should be used sparingly to convey an idea or an emotion.
    A logo that’s designed to get attention instead of conveying a positive image sends a bad message to the people with whom you correspond. Being cute doesn’t buy your company the image of a solid and important business.
    The letterhead must identify and send a clear message about the sender, built it must not obscure the letter that is written on the printed sheet. If you want to include a log of information about your company with each letter, do it on a separate insert.

What is the author’s main purpose in writing this article?