142 Envelope and Card Specifications

142.1 Color

Light–colored envelopes and cards that do not interfere with the reading of the address and postmark must be used. Do not use brilliant colors.

142.2 Quality

Envelopes and cards must be constructed of paper strong enough to withstand normal handling. Highly glazed paper or paper with an overall design is not satisfactory.

142.3 Shape

Rectangular.

142.4 Minimum Size

1. Length: 5–1/2 inches.
2. Height: 3–1/2 inches.

142.5 Window Envelopes

Window envelopes must be used under the following conditions:

1. The address window must be parallel with the length of the envelope.
2. The address window must be in the lower portion of the address side.
3. Nothing but the name, address, and any key number used by the mailer may appear through the address window.
4. The return address should appear in the upper–left corner. If there is no return address and the delivery address does not show through the window, the piece will be handled as undeliverable mail.
5. The address disclosed through the window must be on white paper or paper of a very light color.
6. When used for registered mail, window envelopes must conform with the conditions in DMM 503.
7. Open panel envelopes, i.e., those in which the panel is not covered with a transparent material, are not acceptable in international mail.

142.6 Bordered Envelopes and Cards

Envelopes and cards that have green–colored bars or red– and blue–stripped borders may be used for the sending of First-Class Mail International items.