BACK GUM - Also called seam gum. It is the adhesive used to seal the seams on the back of the envelope to form the envelope pocket.

BANDING - A counting method in which a paper band is placed around a specific number of envelopes. Most commonly used for greeting envelopes.

BANGTAIL - A booklet style envelope with an extension on the bottom flap that is "perfed" at the throat. This extension, or tail, is usually printed as an order form. Bang tail envelopes are commonly used by mail order companies and as credit card statement remittance envelopes.

BANKERS FLAP ENVELOPE -  Also known as a wallet flap, this envelope is readily available in the larger commercial envelope sizes and is used for heavy mailing applications, such as bank statements that must get through the mail system intact and secure.

BAR CODE - Used by the Postal Service to speed mail processing. Generated by the Post Office as mail passes through OCR scanners or pre-printed by the manufacturer. If not pre-printed, space must be available on the bottom right of the envelope for the bar code.

BARONIAL - Often used for announcements and greeting cards, this envelope has a large pointed flap and diagonal seams, and is available in five popular sizes. Companion panel and plain cards and folders are readily available in the standard sizes.  Used most often for social correspondence, including announcements, greeting cards and invitations.

BASIS WEIGHT - The weight of 500 sheets of a standard size paper of a given grade. For example, 500 sheets of a 25 x 38 Basis 80 text paper weigh 80 pounds. In another example, 500 sheets of 17 x 22 Substance 24 bond or writing paper weigh 24 pounds.

BLANK - The die cut paper in the form of an envelope prior to folding.

BLEED - When the printed image extends beyond the fold of an envelope or off the edge of an envelope blank.  Envelopes with bleed generally must be printed before they are folded, since the fold line runs through the printed image.

BLIND EMBOSS - Raised design stamped in paper, without foil or ink. Can be done before the envelope is folded so that design is not debossed onto the back of the envelope.

BLOCKING - The premature activation of the front seal gum in areas other than those directly above the back seam gum.

BOND GRADE - Grade of writing or printing papers, often used for letterheads and matching envelopes. Characterized by strength, rigidity, relatively low opacity, and erasability. Sometimes with cotton fiber content.

BOOKLET - An open side, double side seam envelope, usually having a wallet style flap. This envelope comes in many standard sizes. The most popular size is 9 x 12.

BOTTOM FLAP - The section of the envelope folded up from the bottom score to form that portion of the back of an envelope.

BRIGHTNESS - The light reflecting property of a paper. The more light it reflects the higher its brightness. A bright sheet offers the best print quality and appearance.

BULK PACK - Efficient way to package envelopes by putting directly into a corrugated carton. Not utilizing an interior box which is in turn packed into an exterior carton.

BUSINESS REPLY ENVELOPE (BRE) -  Also known as a Return Envelope. These envelopes can be any style or size. The distinct difference is "Who pays the postage?" A BUSINESS REPLY is pre-printed with a first class permit and return address in which the original sender pays for its return. It is commonly referred to as B.R.E. The BUSINESS RETURN has a pre-printed return address, but the individual returning the envelope must apply postage. The most commonly used envelopes for either purpose are the commercial style-sizes 6 1/4, 6 3/4, #9.