Terminology for Antiquarian Books
A good website should inform and make consumers confident that they understand what is being said and what they will get when they buy an out-of-print or antiquarian book. Unfortunately, the terms used in the book trade are so numerous and have so many variations that it would take five or six catalog pages to describe them all; hence, we list them online here to save paper and to make them easier to update.
Remember that some dealers use slightly different wording than we do. We have tried to use as many of the words as we have encountered over the years in the book trade, but, no doubt, we probably will still miss a few.
Nothing is more confusing than the term “first edition.” Even within the book trade it is used with a great deal of variance, and you will encounter collectors and dealers not always agreeing on an exact definition. However, the authoritative and much venerated Chicago Manual of Style has a definition for the term, and we feel it is a good one. It says that a first edition becomes a second edition if the binding or text or illustrations have been substantially altered from the first to the second printing. So, if a book is printed in 2009 and again in 2010 and the binding, text, or illustrations have been substantially changed, you now have a second edition. However, if a book is printed in 2009 and again in 2010 and very little if anything is changed, what you have is a first edition/first printing (2009) and a first edition/second printing (2010).
A very popular book may be printed again within months of the first printing and that would become a first edition/second printing, assuming that nothing substantial was changed. In practical terms there is almost always a physical difference between the first printing and the second printing. These can include differences in paper and binding materials, dust jacket, retail price, or other very small deviations from the original. But can any of these changes be discerned by the collector? And is it still possible to detect these changes fifty or more years later? Practically speaking, the answer to both is: not very often! It must be evident that these very subtle changes are only apparent to a few people at the publishing company, and only then for a short period of time. (As an aside, we here at Safari Press often have to look through numerous records to know the exact printing of one of our own books—even a few years after the event.)
Publishers of old often did not change the date of publication when they reprinted the title, and a printing sequence string (see below) did not exist till the late 1970s, so today it is very hard to know if a book published in 1895 is a first or a second printing. In addition, even if you went to the trouble to hire a paper-manufacturing expert who can conclusively prove in a lab that the paper from copy X was made at a different manufacturer from the paper in copy Y, it still gives you no clue which came first—given the possibility that the printer of old could have changed the brand of paper in the middle of a press run.
There are sometimes physical clues as to which printing a book may be, but, as you will see in our next example, these can also be confusing. The book trade generally assumes that the more elaborate the copy, the more likely it is to be the first printing. Let’s take Maj. Percy Powell-Cotton’s In Unknown Africa (London, 1904, Hurts and Blackett) as a good example of this. The 1904 edition is bound in a dark blue, pebbled-textured cloth with a stamped giraffe head on the front cover. Some copies have this giraffe head in gilt while others have it in black. As gilt stamping at the turn of the twentieth century involved real gold-leaf foil, it is reasonable to assume that the gilt giraffe is the first printing and during subsequent printings the publisher pinched pennies and used black foil.
However, is this really so? While we cannot prove that the gold-foil giraffe head signifies the first edition/first printing, we feel it is a reasonable assumption. There is, however, still a degree of uncertainty in our claim.
First Edition, First State, and Best State
We have identified when a book is a first edition and then we identified when it is a first printing. What is meant, then, by the term “first state”? Generally, a “first state” refers to a treatment, addition, or omission that the first so-many-copies-of a press run received before this was altered and then the press run was continued. A good example of this is David Livingstone’s Missionary Travels (London, 1857, John Murray). Some copies of this book have three illustrations in color (the fold-out frontis and two other plates), and it is generally accepted among collectors that these copies with color illustrations are the “first state.” Is this really true? Possibly.
However, the copies with the colored illustrations could have been done at the end of the print run, not the beginning and, hence, are not “first state” in the strict traditional sense of the term. Actually, the term “best state” should probably be used, and, in most cases, this might be the better descriptor as we often do not know which state came first. In the case of the Livingstone book, it can be fairly remarked that the copies with the color illustrations are certainly the “best state” as they are far rarer and prettier than those copies with uncolored plates.
With modern manufacturing, the term “first state or best state” has become rare. The speed of manufacturing 3,000 books today prevents a publisher from calling a printer and saying: Stop the presses—we need to alter something on page 83. Printing 100 years ago was a much slower process, and if a mistake was found halfway into the book, or an color illustrations needed to be added, the publisher could have that signature re-typeset and have the printer make corrections or have part of the plate run colored. In days gone by, book binding was also a slow and elaborate process, and it could take months before an entire print run was bound. During this time, different cloths and stamping might be applied. In addition, plates and maps were often printed on different presses or even completely different printers. With modern technology, this is unlikely to happen.
Printing Sequence String
Since the 1980s, most publishers in the Western world use what is known as a Printing Sequence String. This is a string of numbers that is found on the copyright or ISBN page in the front of a book and refers to the print run of the book. This string of numbers is usually from 1 through 10 (or more) with a space between each. If the book is being printed the first time, you will see 1 2 3 4 5 6 7 8 9 10; if the book is a second printing, you will see 2 3 4 5 6 7 8 9 10; and if the book is a third printing, you will see 3 4 5 6 7 8 9 10. Thus, with each subsequent printing, a number is dropped from the beginning of the remaining sequence. Remember most publishers apply this for printings only. Once a book is revised or significantly changed, it becomes a second or subsequent edition, and the printing sequence string starts afresh. Please note that the consistency of the application of these Printing Sequence Strings was not very uniform in the early years of this feature.
This is a rectangular box with six sides, one of which is left open so that a book can be pushed in. A slipcase allows the spine of the book to still be visible yet protects the book from the elements. Slipcases are made from hard carton, are normally covered by paper or cloth on the outside, and are lined with white paper (white faced) on the inside if they are of higher quality. Slipcases can be decorated and/or stamped, or they can be plain. In rare cases, a slipcase can be “double reversed.” In that case a book is placed inside a slipcase and then another slipcase is placed over the book and the first slipcase, thus covering the book’s spine from the elements.
A chemise was the medieval precursor of the modern dust jacket. It was a slip-on cover of leather or a textile, such as velvet or linen, that protected the binding of a book and its fore-edge. Chemises varied in form from high-grade, luxurious embellishments for a Book of Hours (a medieval illuminated manuscript) to functional wrappers for administrative records and library books. It is thought the name derives from the chamois, a wild mountain goat, whose leather was often used to make a chemise.
There are numerous examples of variant bindings on books, especially those found before WW I when the manufacturing of books still required a lot of handwork and machinery was much less employed. The number of variations in bindings can be astonishing to the modern-day consumer. For instance, we have managed to identify no less than six different bindings of the 1891 edition of Hindu Koh by Maj. Gen. Donald McIntyre. Why so many different bindings of books were created for one title is hard to understand, but, while surprising, there can be no doubt that it is so. Some reasons and theories offered are that cloth was made in small batches, and thus the first 100 copies were bound in brown and the next 200 in blue. Another reason for variant bindings is that many publishers from the 1880s to the 1920s likely ordered pages printed, folded, stitched, trimmed, and sown into book blocks but then kept these book blocks (or the printer did) till they were needed and only then had them bound. It is not hard to see how this type of stop-and-go manufacturing would yield a lot of different binding and stamping variations.
Variant bindings fall in a couple of categories: those that are different but no less attractive than the rest and those with superior or lesser quality dissimilarities. In the case of the McIntyre book, the books we documented were bound in various cloth colors but were otherwise identical, and any one was no less attractive than another, and the same can be said of the stamping on the books that, while they varied slightly, none is more or less attractive than the other. There are variants that are clearly superior or inferior. In some cases publishers did “plain vanilla” bindings that have a lot less decorative stamping than the fancier versions. In other cases, “export” or “colonial” or “tropical” bindings were used for certain markets, and these are often less attractive than the standard version.
So, what is a collector to do? A good, experienced dealer should and will indicate variant bindings if they are known. Remember, there will be hundreds of variant bindings even in the niche-collecting market of hunting and shooting books; consequently, don’t expect general book dealers to know all the various bindings found in, say, horse-breeding books. Even expert dealers in a niche market will freely admit that after a lifetime of dealing in their chosen specialty, they have not seen all variant bindings and never will.
US versus UK Edition or London versus New York
Which edition is more valuable, the American or the British edition? This complicated subject is well worth understanding. As the US economy increasingly grew in size in the period from 1890 through 1920, more and more books were published simultaneously—or almost so—in the UK and the US. For financial reasons publishers sought an overseas partner with whom they could share a print run to cover the expenses of a printer. The book to be printed were then given different title pages, copyright pages, covers (sometimes), dust jackets, and, yes, surprisingly often entirely different titles. When a UK and a US publisher teamed up on the same book, then, in some cases, the book would be printed in both the US and the UK from the same typeset version of the book. However, in most cases, books were printed in only one country; they were then provided with slightly different bindings and frontal pages and shipped off to their respective markets.
This has led to confusion as to which edition was printed first. In some cases, we have found that books for one market were not dated, and in other cases (rarer), books were released in one market, say in 1929, and in the other market in 1930. It is also possible that some books physically are larger or smaller from one market to the next, and though this is quite rare, in some cases even the content of the book is not quite the same in the US and the UK editions. As a general rule in big-game hunting books, it can be said that collectors in this niche prefer the British versions of books. As a general rule, we concur, but in some cases the tables are turned and some real oddities exist. For instance, the British version of Pondoro by John Taylor was not only published a year after the US version but it also misses the last chapter on racial differences between African people the US edition features. Another is Stigand’s Hunting the Elephant in Africa; all copies we have seen were printed by the Norwood Press in MA and both the London and New York editions are dated 1913. The UK copies we have seen have “New York and London” printed on the title page and the US copies only “New York”. Most UK copies we have seen came in red cloth while the US editions came in various colors, most often dark blue; what is most interesting is that the US editions all have a stamped set of kudu horns on the front cover while we have never seen a UK edition with this stamping. In our opinion the US edition is the nicer of the two.
There are a hand full more of examples like this. This has brought forth a never-ending debate as to which printings were or are more desirable.
A clamshell is a particular type of bespoke protective box that is made individually for a specific book and is used to preserve rare books and papers. It has a hinge, normally of cloth, on one of its three sides, allowing the book to lay flat inside the bottom (or tray) of the box while the top-side and spine side can be opened and extended for viewing the book. The top and bottom and bottom sides of the clamshell fit into one another snugly to provide complete cover and protection for the book inside. A clamshell is normally covered in cloth, and the spine can be made to look like a book so that at first glance when you see one on a shelf, it seems as though you are looking at the actual spine of the book.
In days gone by, books were bound in real cloth as well as leather and vellum. There were numerous types of cloth with trade names such as buckram, linen, sail cloth, etc. All had slightly different textures, and they all contained a high percentage of (cotton) fiber. Today these types of cloth are quite expensive, and only publishers of quality books will continue to use real linen.
Cloth is bound around heavy paper boards in the front, back, and spine. Most modern books today are bound entirely in artificial “cloth,” such as Kivar, or if the publisher wants to save even more money, the spine is covered in Kivar or something like it, and the boards are covered with paper. (See Boards or Covers.)
Boards or Covers
The boards form the front and rear panels of a book and are connected via the spine with binding materials. Strictly speaking, the “boards” are a carton-like substance that is covered by binding material; however, in book collecting, when mentioning a board, it is often assumed that it is both the carton and the cloth covering it. The carton is often called Davey board after the Davey company, founded in the UK around 1842.
Stamping is the application of a design onto a book’s spine or covers using heat, pressure, and metallic foil paper. A metal plate, called a die, is sculpted into a design—letters, landscapes, people, animals, or whatever creative drawing the artist can conjure—and then heated. After the heated die comes into contact with the foil, pressure on the die causes the foil image to stick to the book. Before WW I the quality of the dies and the foils used as well as the craftsmanship of the bookbinders was such that very detailed scenes could be depicted with great realism. Unfortunately, the art of this type of stamping has been lost, and today it is only somewhat found on the most elaborate handmade bindings. Because of the labor involved, hand-crafted bindings are very expensive.
Pages of a book are printed on very large sheets of paper, and each sheet of paper has multiple pages printed on each side. Each of those sheets of paper comprise a signature. Once printed, a signature is then gathered, folded and sown or glued as a unit; at this point the pages will be in their correct sequential order. Depending on the size of the book and the size of the press, a signature is normally 8, 16, or 32 pages. If you take a book and look at the top of the book block (pages), you can see faint traces of these groups of pages that have been folded into one another. Each represents a signature of 8, 16, or 32 pages.
This refers to a book’s binding that is decorated with either stamping or printing. Stamping can be in almost all colors of the rainbow, although the most traditional and most expensive stamping is done with gold leaf, known as gilt in the book trade. Cloth can be printed; this was often done on lighter color cloths with a darker color ink to provide a contrast, but sometimes the cloth was dark and the ink light. Good examples of printed cloth are the front cover of Count Potocki’s Sport in Somaliland (1900) and Edward Buxton’s Two African Trips (1902).
A faded spine occurs when it is exposed to prolonged sunlight or artificial light. This affects the value of the collectable book.
Condition of Corners
Corners can be worn, bent, or have the board showing. When the corners are worn, the cloth is worn but not completely missing. Corners can also be bent and/or the cloth around the corners can be frayed. If the board is exposed, that means the cloth has worn away, and the normally hidden boards can be seen. These conditions negatively affect the value of a collectable book. When the corners are sharp, it means they are as close to original condition as they were when they left the bindery; the corner itself still retains its 90-degree shape and is not bent inward or outward. Pristine corners increase the value of a collectable book.
Scuffing is a term used to describe the condition of a binding. A scuffed binding or page has received very small scratches rub marks from objects scraping against them.
Photo Inset, Art Inset, Label Inset
Sometimes a photo, printed paper illustration, or a leather label (with stamped lettering) is placed on the front or back cover of a book to decorate it. These are known as “insets.” To inset a piece of art on the cover of a book, the cloth is first embossed to make a small impression in the cloth and board and then the label or illustration is glued onto the cover. In rare cases, jackets have labels glued onto them, and the effect is somewhat similar.
A spine label is a rectangular, round, or oval piece of material that is attached to a book spine; the label material often contrasts to the material of the book. Labels can be made of leather or cloth; older books often sport a paper label. A label can be printed or stamped and is, most often, a descriptive tag that indicates the author and or the title.
A rebacked spine is one that has had its original backing material replaced. Depending on how neat of a job was done and how much cloth was worn away before the spine was rebacked, it can be hard to see if a book was rebacked, especially after ten or fifteen years. Rebacking a book requires a restorer to take the book block (bound pages) out of its covers, replace the backing material on the spine, and place the book block back into the covers. When rebacking a spine, the cloth on the spine is kept intact as much as possible. Originally the cloth covering the boards was a continuous piece from the front to the back covers, and the restorer will try to maintain that continuous original flow in the restoration. In most cases the end papers are replaced when a book is rebound.
Re-laid Spine or Laid On (Spine)
A re-laid spine is a spine that has been detached from the boards, likely trimmed along the edges, and re-laid onto a new spine. This can clearly be seen along the bottom, top, and the sides. A re-laid spine is a far more radical procedure than a rebacked spine.
A recased book is a book whose boards and spine material have been replaced while preserving as much of the original cloth as possible. This is achieved by re-laying the original cloth on top of the new cloth, and it is done in order to retain as much as possible the look of the original book.
A book is “sewn” when the pages are threaded together in signatures. This is called Smythe sewn after David Smythe who is thought to have invented the mechanical sewing machine. Modern books are often not sewn but have “burst bindings.” This is a process by which half-moon shaped holes are created along the edges of the spine of the book block, glue is then applied, and the book is bound by attaching it to a stiff paper spine and boards. If a book is resown it means the page signatures were taken out of the binding the old tread removed and new thread applied and the whole reassembled.
The inner hinge is where the book block meets the binding and where the one-piece endpaper holds the two together.
The outer hinge is the area of the binding where the spine meets the boards.
The endpapers are the papers that connect the boards to the book block.
The top and bottom of the spine are not attached to the boards.
Raised Bands or Hubs
Hubs are raised, horizontal bands/ribs/ridges on the outside spine of a case-bound book. In the olden days, pieces of small rope were attached at a 90-degree angle to the paper book block; these small ropes helped both to bind and strengthen the book. In other words, they were the sutures that held the book block together. When these ropes were covered in the binding process, they formed a raised band or hub. This method went out of fashion over a century ago, and hubs/bands on the spine today are purely stylistic. They are considered highly decorative and can be found on fancy bindings, especially leather bindings.
Three-Quarter (¾) (Leather) Binding
This is a binding whereby the spine and corners are covered in leather or a different color or type of cloth. A three-quarter binding means that the spine and all corners of the boards are in a different material.
Half (½) (Leather) Binding
A half-leather binding is one in which the spine and some of the boards are covered in leather or a different cloth but the remainder of the boards is a uniform other material.
Gilded and Colored Edges
A book has three edges, which were formed when the pages were cut on the top, front, and bottom. Before WW I, gilding an edge meant applying a very thin layer of gold foil to the edges of the paper so that when the book was closed and the pages pressed tightly against each other, a barrier formed to prevent moisture, dirt, and dust from entering in between the pages. A book that has had its edges gilded looks rich and goes very well with lovely decorative leather bindings. After WW I, the use of genuine gold foil was mostly dropped and some publishers started applying colored ink to the edges, but its resistance to the elements was nil. After WW II, manufacturers in rare cases again started gilding book edges, but genuine gold foil was no longer used. Most often the top edge was the only edge gilded, but in rarer cases all edges were gilded. High-quality custom binders continue to offer gold leaf gilding for book edges for those who want the real thing and can afford to pay for it. Silver foil has also been used as an alternative.
Decorated or Printed Edges
Binders sometimes printed the three edges of a book block so that they would display images relevant to the content of the text. This was most often done in color.
The marbling of pages edges was introduced near the end of the seventeenth century, mainly on trade books bound in calfskin or sheepskin, yet marbling edges on fine bindings did not occur regularly until the closing years of the eighteenth century. To marble the three edges of a book, the binder applies a multicolored, swirled pattern designed to look like marble.
Rebound in Cloth/Leather
A rebound book is a book where an entirely new binding is applied to the book block.
An endpaper is twice as large as a regular book page and partly glued to the inside of the cover of a book. Endpapers can be blank unprinted paper, colored paper, or paper printed with various images such as photos, maps, and logos.
Marbled endpapers are multicolored papers that display a wavelike or marblelike pattern. Marbled endpapers can be either hand colored—the most expensive—or be printed (still expensive). Either way they are a very pretty addition to a book and are often found on more expensive leatherbound books.
A fold-out map is a map that is printed on a piece of paper that is most often larger than the page size (trim size) of the book. In order to see such a map, the book has to be opened to the map’s location and laid flat, and then the map is unfolded from one to multiple times in order to see it. A folded map is nearly always attached to the book block yet is a separate unit. Care must be taken not to rip the old paper of folded maps and to re-folded it correctly when finished.
This is typically a folded map that sits in a specially created pocket, normally in the rear of the book. Unlike a fold-out map, it can be removed as it is separate from the book.
There are various forms of soiling, dust soiling being the most common. All leave marks on the cover of the book and sometimes on the pages.
Offsetting or Ghosting
These are terms used to describe text or images that have left an imprint on the opposite pages and can happen for various reason. For instance, the ink on page one is not quite settled or becomes unstable over time and makes an impression on the opposite page. Older books with plates often have this problem, and often it is a problem of a chemical reaction of the ink or colors used. In some other cases, the text may start chemically “bleeding through” the page, and when that happens, it will show on the back side of the same page.
This is a term used to indicate acidification of the pages, which can take various forms. Among these are spotting (common), an even browning of the entire page, or even a local browning spot because an object was exposed to the paper for a long time (normally another piece of paper). Since the advent of acid-free paper, foxing has disappeared from book pages. As an aside, never leave another piece of paper, photo, or object on the page of an old book as foxing is likely to occur via chemical reactions between the elements.
Library marks are placed on the binding or pages of a book, and they are, strictly speaking, a way of indicating to whom the book belongs. However, in most cases library marks refer to any intuitional library that belongs to a school, church, community, etc. Library marks from these places can take on many forms. Often, they are spine labels or spine lettering adhered in such a way that they are hard to remove, or there can be blind stamps, bookplates, perforations, ink stamps, or glued-on pockets that hold library-lending cards. In some cases, books are rebound in a very sturdy cloth to extend their life since treatment in a lending library can be rough. Old British libraries had the habit of placing (gilt) stamping on the front original cover and/or spine to indicate the ownership of a book. While some of the latter can be rather attractive, in general a book with library marks is less desirable than one without.
Library marks from private libraries are another matter. In general, an ink stamp of the owner’s name detracts from the value of the book; however a bookplate or a pen inscription “From the Library of a famous personality” can add to the value of a book.
Blind Stamp on Paper
A blind stamp on the pages of the book is an impression created by a metal die that looks like a tool from a garage. It has a top and a bottom, and the paper to be stamped is placed in-between it. Once the lever of the device is pressed, it shuts and creates a raised impression on the paper. Often such stamps state “From the Library of XYZ.” A very similar device is used on official papers from corporations and sometimes by lawyers and notary publics. It is generally sound advice not to stamp your books like this. This includes all books but especially books from the post-WW II era, which tend to lose their value with a paper blind stamp.
Blind Stamping on Bindings
Blind stamping on bindings means that a stamp (also called a die) was applied to the covers without any foil so that only an impression is formed in the cloth. These can take the form of a letter or a decoration, and the blind stamp becomes visible because of the indentation into the binding. Debossing—See Embossing and Debossing—is almost the same as blind stamping except that the term debossing is used more if the stamping is an image while blind stamping is used more in case of letters or simple lines/frames.
Embossing and Debossing
Both of these terms describe the pushing of material (paper or cloth) to a level below or above the original surface. This is done with dies and counter dies and is accomplished by squeezing the material between the two dies.
To emboss is to push the image above the original surface. To Deboss is to push the image below the level of the original surface. Both can be done blind, which means no foil is used, or with foil. Embossing is used much more than debossing. In the majority of cases, a paper blind stamp embosses the paper while the stamping on the cover of a book debosses the cloth.
Trimmed Edges and Pages
In modern book publishing, all edges of a book are trimmed. If they were not, you could not open many of the pages when flipping through the book. Trimming is necessary because of the way pages of a book are printed. See “Signature.” Pages of a book are printed on very large sheets of paper, and each sheet of paper has multiple pages printed on each side. Each of those sheets of paper is known as a signature. A signature consists typically out of 8, 16, 24 or 32 pages. If the pages were not trimmed after these giant pieces of paper have been folded, they would—except for a few places—not open. This, of course, depends on how large the sheet of paper is and how many times it was folded. In the old days, a book was left untrimmed on one side and the reader had to take a sharp penknife to open many of the pages of the book. Books can also have untrimmed pages but without the need for opening the pages with a penknife. In this case, the pages were opened (cut) but not trimmed. The pages of such books have slightly rough edges. Modern books have all edges neatly trimmed and smooth, but in the old days, edges were rough and not smooth.
Most post-WW II dust jackets have prices printed on them somewhere. In many cases this is in the corner of one of the dust-jacket flaps. In many cases, if a book was given as a present, the jacket was clipped so that the price was removed. If you are a book collector, it’s important to note that a book with the price clipped from the jacket will be worth less than one without the price clipped, all other things being equal. How important is this? Well, with some books, you are lucky to even find that title with a jacket, especially if it was printed before 1940. So think twice before saying no. However, in cases of modern literature, clipping the price will make a significant difference in the value of the book, especially by authors such as Ernest Hemmingway.
When taking a book out of a shelf and placing it back, the bottom of the boards and sometimes the pages will rub against the shelf. Done often enough, the book will show wear and be less valuable. Big heavy books with a large page count almost always have a certain amount of “sag” where by the pages have rubbed over the shelf.
Dust Jacket, Dust Wrapper (British), Jacket, Dust Cover
In the late 1800s books started to be delivered with jackets, initially simply brown paper with (hardly) any printing on them. Their purpose was to protect the book’s cover and gilt stamping during transport. As time passed, a jacket became a way to advertise a book; consequently, more money was spent on the jackets while the quality of the stamping and the binding of the actual book decreased. Early books with jackets can be considerably more expensive than books without.
As a side note: “Books” roughly from 1840s to 1870s were delivered as loose or bound pages in signatures only. The purchaser then took the book block took to his bindery of choice to have the book bound. These signatures were sometimes wrapped with one or more nicely decorated paper “wrappers” to protect the pages. In most cases such wrappers were discarded by the binders, but in rare cases these wrappers were bound into the book or attached to the binding. Over time, as jackets became more important and popular, various names for them also evolved. That is why there are many variations for the word dust jacket. These include dust wrapper (British), jacket, and dust cover; all refer to the same thing.
In the old days books were manufactured with animal glues as opposed to modern glues that are nearly always synthetic. Depending on the process and the subsequent storage of the book, one might get “bubbling” of the boards and/or spine. If you see this on a book, it is simply the cloth letting loose from the boards because the glue has lost its ability to adhere. A good bookbinder can normally repair such a book rather satisfactorily as long as the bubbling was not caused by extreme humidity.