In the direct mail package, the letter ranks first in importance.  The most effective mailing package consists of an outer envelope, letter, brochure, response form, and business reply envelope.  Keep these guidelines in mind when designing your package. 

Letter

• Form letters using indented paragraphs usually out pull those in which paragraphs are not indented.
• Underlining important phrases and sentences increases results slightly.
• A letter with a separate brochure generally does better than a combination letter brochure.
• A form letter with an effective headline ordinarily does as well.
• Authentic testimonials is a sales letter ordinarily increase the pull.
• A two page letter will out pull a one page letter.

Brochure

• A brochure that deals specifically with the proposition presented in the letter is more effective than a brochure of an institutional character.
• A combination of art and photography usually produces a better brochure than one employing either art or photography alone.
• A brochure usually proves to be ineffective in selling magazines and news stories.
• In selling big ticket products, deluxe large size, color brochures virtually always warrant the extra cost over 11 x 17 or smaller brochures.

Outside Envelope

• Illustrated envelopes increase response if their message is tied into the offer.
• Variety in types and sizes of envelopes pays, especially in a series of mailings.
• Try to imply some reward from simply opening the envelope.
• Don't reveal the total sum and substance of your offer.
• Don't hesitate to employ the good headline words like "new," "now," "how," "special,“ "guaranteed"' . . . and if there's anything free in connection with your offer, don't keep it a secret.

Reply Form

• Reply cards with receipt stubs increase response over cards with no stubs.
• Busy order or request forms that look important usually produce a larger response than neat, clean looking forms.
• Postage free business reply cards generally bring more responses than those to which the respondent must affix postage.

Reply Envelope

• A reply envelope increase cash with response.
• A reply envelope increase responses to collection letters.

Color Use

• Two color letters usually out pull one color letters.
• An order or reply form printed in colored ink or colored stock usually out pulls one printed in black or white stock.
• A 2-color brochure generally out pulls a 1-color.
• Full color is warranted in the promotion of such food products, apparel, furniture, and other merchandise if the quality of color reproduction is good.

Postage

• Third-class mail ordinarily pulls as well as first-class.
• Postage-metered envelopes usually pull better than affixing postage stamps
• A “designed” printed permit on the envelop usually does as well as postage metered mail.