BANG-TAIL: Perforated coupon attached to the body of a return envelope; must be torn off before the envelope is sealed. Used for remittance envelopes and other direct mail applications.

BAR CODE: Pre-printed code used for electronic postal scanning.: Generated by postal service for OCR scanners. Location on the envelope is critical for proper bar code scanning.

BARONIAL:  A style of envelope that has a large pointed seal flap.  Baronial style envelope is usually close to being square; however, the flap and paper used are the most distinguishing feature.  The most common present usage is for greeting cards or social stationery.

BLEED: An image that extends off the page or envelope. Envelopes with bleed should be printed before they are folded. 

BOOKLET: Envelopes with the "open side" flap, open on the long side of the envelope

BUSINESS REPLY or RETURN ENVELOPE: These two envelopes can be any style or size.  The distinct difference between them is, who pays the postage.  A Business Reply is referred to as the envelope that has a pre-printed First-Class Permit and return address on it and the original sender pays for its return.  The business Return has a pre-printed return address but the individual returning the envelope must apply postage. The most commonly used envelope for either purpose are commercial #6-3/4 or #9.  Another frequently used style is the remittance flap which serves as both the mailing and the return envelope.

CATALOG: All envelopes with the "open end" flap are called catalog.

CENTER SEAM: Is the permanent seam that is located approximately in the center of the envelope running from the bottom fold up through the envelope and terminates at the throat.

COMMERCIAL STYLE: These are the most common business style envelopes.  They are "open side" of the diagonal or side seam construction.  Applies to a wide range of sizes both regular and window envelopes.

CORNER CARD: Return address and other company identification in the top left corner. 

DIAGONAL SEAM: A seam running diagonally from the bottom fold and the corner up toward the throat of an envelope.

FACE: The front of the envelope.

FLAPS EXTENDED: This term is used to describe leaving the flap in a vertical position (not folded down).

FLAPS FOLDED DOWN: A term to describe folding the flaps down against the back of the envelope.  Most envelopes are packed in boxes with the flaps folded down.

FULL VIEW PICTURE WINDOW: Large window envelope that allows full view inside of the contents of the envelope.

INSIDE TINT: Printed design on the inside of the envelope for added security. 

LATEX SEAL: Is  a self-sealing adhesive that requires no moisture.  Two gum surfaces are required to create a bond when they are brought together.

OPEN END: A style of envelope on which the opening is on the short side.  All open end envelopes are called catalog or coin envelopes.

OPEN SIDE: A style of envelope on which the opening is on the long side.  All commercial envelopes are called open side.

REGULAR: A style of commercial envelope that does not have a window panel in it.

REMITTANCE:  A large style seal flap of approximately the same size and shape of the envelope itself.

SIDE SEAM: Is an envelope seam that runs along the side almost parallel to the side fold.

ZIP STICK: Is a self sealing adhesive with a protective strip. No moistening is required.