Backbone
The back of a bound book; also called the spine.

Backing up
Printing the back or reverse side of a sheet that has already been printed on one side.

Band
(1) A strip of paper, printed or unprinted, that wraps around loose sheets (in lieu of binding with a cover) or assembled pieces. (2) The operation of putting a paper band around loose sheets or assembled pieces.

Bang-tail (envelopes)
Perforated coupon attached to the body of a return envelope; must be torn off before the envelope is sealed. Used for remittance envelopes, order envelopes and other direct mail applications.

Banknote paper
Highly resistant, age-resistant, suitable for four-color printing, with watermark and other falsification safeguards such as embedded metal strip. Often containing cotton fibers (also see rag paper).

Bar code (envelopes)
(1) Generated by the United States Postal Service as mail passes through OCR scanners. Space must be left at the bottom of an envelope for the bar code. (2) Pre-printed code used for electronic scanning: retail products, filing, materials handling and photofinishing systems.

Baronial envelope
An envelope generally used with announcements.

Base color
A first color used as a background on which other colors are printed.

Baseline
In typesetting, the invisible line on which letters and numbers are set.

Basic size
The standard sheet size of a given grade used to establish the basis weight of a ream (500 sheets) of a given paper grade. The basic size of text-weight papers, for instance, is 25" x 38" and the basic size of cover stock is 20" x 26".

Basis weight (also see grammage or substance weight)
The weight in pounds of a ream (500 sheets) of a particular paper grade that has been cut to its basic size in inches. Example: a ream of 25" x 38" text paper would weigh 70 lb. The basis weight of papers suitable for watermarks ranges from 16 lb. to 28 lb., with 24 lb. being the preferred weight. A metric system is used outside of North America.

Bindery
A process of perforating, folding, trimming and eventually binding a printed piece.

Binding
Attaching sheets into a single unit by adhesives, sewing, stitching, metal prongs, snaps, etc. The operations that comprise collating, perforating, and folding the elements of a form into the finished product, e.g., a book or brochure. The most common styles of binding are:

Case or edition binding: Commonly used for hard-bound books, case binding brings folded sheets together into signatures, which are sewn together with thread and glued to a spine, with gauze extensions to hold together the end papers.
Mechanical binding: Stacked single sheets are punched with a hole along one edge and bound together with a plastic comb or spiral ring.
Perfect binding: A stack of single sheet papers are glued together along one edge and wrapped with a cover sheet.
Saddle stitched binding: Folded sheets or signatures of paper are gathered together, one inside the other, and placed over a "saddle," then stitched or stapled along the spine with wire.
Side stitched binding: Single or folded sheets of paper are stacked together and stapled at the edge.

Binding edge
The edge where the binding will be done.

Black printer
In four-color process printing, the black plate made to give definition to neutral tones and detail.

Blank (envelopes)
A die-cut sheet of paper before it is folded into an envelope.

Blanket
In offset lithography, the rubber-coated fabric clamped around the blanket cylinder that transfers the image from plate to paper.

Blanket contamination
Unwanted matter that becomes attached to the offset blanket and interferes with print quality.

Blanket creep
Movement of the blanket surface that comes in contact with the printing plate or paper.

Blanket cylinder
The printing press cylinder on which the blanket is mounted.

Blanket pull
The tack between blanket and paper.

Bleach
Chemical, usually chlorine, used to whiten pulp.

Bleaching
A chemical treatment used to brighten, whiten, purify, refine and balance pulp fiber. Bleaching also adds to the sheet's strength and durability.

Bleed
(1) In printing, an image or printed color that extends to the trimmed edges of a page. Bleeding one or more edges usually increases the amount of paper needed and the cost of print production. Envelopes with bleed generally must be printed before they are folded, since the fold line runs through the printed image. (2) The migration of ink into unwanted areas.

Bleed-through
Occurs when printing on one side of a sheet of paper shows through to the other side.

Blind emboss
An embossed (raised) letter or image stamped in paper without the use of ink or foil. Envelopes should be embossed before they are folded so that design is not debossed onto the back of the envelope.

Blueprint
In printing, a type of photo print used as a proof. It can be folded to show how the finished printed product will look.

Bond paper
Strong, durable writing paper, consisting of wood, cotton or both; most commonly used for letterheads, stationery, business forms, etc.

Bonding strength
The ability of paper fibers to bond to one another. The stronger the bonding, the less likely the fibers are to "pick" or come loose on press. Bonding strength not only affects runnability, it is essential for smooth scoring, folding and special techniques such as engraving and thermography.

Book paper
A general term used to define papers that are most suitable for book manufacture.

Booklet
A printed piece bound together, containing a few pages.

Booklet (envelopes)
1) A large, open-side envelope for catalogs, annual reports, brochures, etc. This style is gaining popularity over traditional catalog (open-end) envelopes because it can be used with automatic inserting machines. 2) Also refers to commercial open-side envelopes with two side seams.

BRC (envelopes)
Business Reply Card.

Brightness
The percentage of light in a narrow spectral range reflected from the surface of a sheet of paper. Brightness is not necessarily related to the whiteness of the sheet, but refers to the amount of light reflected back to the viewer. Bright sheets illuminate transparent printing inks and provide cleaner, crisper colors. Paper, paperboard and pulp are measured through a lab test to determine the degree of reflectivity as measured by blue light to determine their brightness level.

Brightness scale
The amount of light reflected by paper expressed as a percentage.

BRM (envelopes)
Business Reply Mail.

Bristol paper or board
A high-quality, heavyweight paper; sometimes made with cotton fiber prepared or glued together and made to a caliper of 0.006" or higher.

Bulk
The degree of paper thickness, technically determined by measuring the thickness of a specified number of sheets under a specified pressure. It takes fewer sheets of bristol, for instance, to create a one-inch deep pile than it would for a less bulky text weight grade. In book printing, the number of pages per inch for a given basis weight.

Bulking dummy
Unprinted sheets of actual paper, folded in the signature size and signature number of a given job, to determine bulk.

Bump
One or more colors added to the four-color printing process to help strengthen a color or colors in a specified area of the printed piece.

Bursting strength
The point to which paper can withstand pressure without rupturing.

Butted joint
Joining two webs of paper, placing them end-to-end and pasting a strip over and under to make a continuous sheet without overlapping.