Below is a list of terms, with an explanation, that will help you to understand reviews and discussions about physical Bibles. The better the quality of the Bible that you are looking for (and with that a higher price) the more important it is to understand what you want in the quality of these parts.
Art-gilt Edges: A decorative finish added to the page edges using colored dye. This color is seen when the pages are fanned out. Red, blue or salmon are the most popular colors used but there are many others, even prints done as art-gilt edging. See Gilt Edges for a finish that is put on top of the art-gilding. Note you will see this term as “gilt” or “gild”.
Cover: The front and back covering of Bibles. Made from a wide array of materials from basic paperbacks, hardcover, imitation leather, and leathers. Leather covers can be cheap bonded leather (partials of leather glued together) to the more exotic and expensive cowhide, goat, or even shark, elephant, or alligator. All these come in various colors.
End Paper (End Sheets): Endpapers are the first and last pages of the Bible which are glued to the cover boards (front and back). Often these endpapers will be of heavier weight and decoratively patterned, and often marbled with a cloth hinge for reinforcement. In premium editions, they may be made of leather. Often referred to as a pastedown or end sheets; paste-down is the page which has been glued to the board and the other side is known as a free endpaper.
Gilt Edges: A decorative finish in which a gold or silver-colored metallic foil is applied to the edges of the pages after they have been cut and rubbed smooth.
Gilt Line: A plain gold line or ‘frame’ stamped inside the covers around the perimeter.
Headband & Tailband: Headbands are colored threads which are wrapped around a core of some sort and are then sewn through the signatures, filling space left between the spine and the book block. Their purpose is to help lessen damage to the book when it is removed from a shelf by its top edge. It also helps to some degree in keeping the sections upright. Also referred to as endbands.
Hinge / Joint: The Hinge of a Bible is the section between the cover boards and the spine. It’s the part that bends when the Bible is opened. The hinge is inside the Bible and the Joint is the view of this part from the outside.
Line Matching: A typesetting technique that matches the lines of text on one side of a page to the lines of text on the backside of a page in order to minimize “ghosting” or “show through” of the print. The goal would also be to have the lines of text on all page on matching locations, again to minimize “ghosting”.
Perimeter Stitching: A line of stitching around the perimeter of many premium Bibles which adds beauty as well as strength to the cover.
Raised Ribs: Raised Ribs or Bands were originally the result of cords (or thongs) used during the sewing process which were affixed to the signatures and used to hold the Bible covers on. Later on, in the binding process, the spine or backbone would be covered and the bands would be raised above the rest of the spine. With modern binding technics, these cords are no longer needed but raised ribs are still add for a decretive touch.
Ribbon Markers: Ribbon markers allow you to keep your place in your Bible as a bookmark while reading or looking up other passages. Three ribbons are the optimum number in my opinion. The finest are made of silk.
Signatures: Signatures are stacks of two or more pieces of paper which are folded and grouped together ready for sewing. Each of the signatures are bound together individually and later bound together as a whole forming the text block. In the bottom middle of the picture above, these are the sections in the “Text block”.
Smyth Sewn Binding: A Smyth Sewn bookbinding is the highest quality bookbinding available on the market today, as the pages are physically sewn into the book using binder’s thread, and further reinforced with fabric backing and adhesive. Smyth Sewn bindings use thread to sew through folded signatures of a book. All of the signatures are likewise attached together with thread creating what is called the book block. The book block is further strengthened using flannel and adhesive on the spine.
Other binding options are glued or lesser quality sewing techniques.
Spine (text block spine): The spine is where the signatures and text block are bound. Usually, the spine will contain important book information so it can be easily found when on a shelf. Information might include the book’s title, name of author, and publisher’s name or logo. Also known as the back, or backbone.
Tail: The Tail is the bottom part of the Bible.
Text block: The block of internal pages that make up the Bible.
Yapp/Semi Yapp: A Bible cover, usually on premium leather Bibles, extending beyond and folding over the page edges to protect them. A full yapp would completely cover the page edges when folded.
Until the next time we see you here at CultivatingFaith.org, God Bless! #CultivatingFaithOrg
Checkout this site on 15 detailed diagrams that show how a book is made.