Part One

You can’t judge an apple by looking at a tree
You can’t judge honey by looking at the bee
You can’t judge a daughter by looking at the mother
You can’t judge a book by looking at the cover.
— Bo Diddley / written by Willie Dixon

Are you looking for reading recommendations?

or maybe a Bo Diddley recording?

If so, you are probably in the wrong place.

On the other hand, if you have books you want to keep for a long time, and perhaps pass on to your children, you may find this useful. Ditto if you work in a research library. Ditto if you’ve ever wondered how books are put together. We are talking here about things that affect a book’s chances of long-term survival.

Book conservators know how books are made, and importantly, why and how they fall apart. So I’m going to share some secrets about how to distinguish between a book that is likely to last and one that may not. Hint: As the title of this post suggests, one with a worn cover could very well be a better choice than one that looks good from the outside. In truth, the choice is not usually clear-cut — not by a long stretch. Nevertheless, better choices can be made, and made more easily, when armed with information about the physical aspects of books and how they are put together.

Book conservators work hard to keep books in good condition so that they will be there when you need them. But do you know what has helped the survival of our collective intellectual record more than the collective efforts of book conservators?

Lots. Of. Copies.

Any particular book or journal is likely to be found on the shelves of many libraries. Everybody knows that, and that is a good thing. And an individual library very likely has duplicates even within its own collection.

Redundancy is good in the world of information preservation, whether it is physical books or backups of your computer files. When bad things happen to good books — as they do — there will still be other copies.

So why worry about better or worse copies when we have lots of them?

Well, in recent decades the cost of maintaining vast print collections has become a pressing problem for libraries. The space devoted to books diminishes a library’s capacity for other things, such as study space for patrons. When libraries run out of space, difficult choices often have to be made.

Since the 1950s, when post-war prosperity led to increasing rates of collection growth, libraries have used many strategies to cope. Microforms reduced the footprint of voluminous materials such as newspapers. Compact shelving was added. Interlibrary lending meant a library did not have to acquire every book. When those measures were no longer enough, high-density storage facilities were built to house books by size on 30-foot-high shelving. But today many libraries have filled up these facilities too, and financial support for yet more space has been hard to come by.

So what now?

You see where I’m going here. Shedding some of the copies would seem like a reasonable next step, especially older materials, which are no longer used as much as they once were. So this is indeed what many libraries are up to these days — withdrawing some copies, either within their own collections or in collaboration with other libraries.

So then, how does one decide which are the best copies to keep? This is where knowing how books are made comes in.

In Part Two, I’ll get all technical and talk about how you can distinguish between a book that is likely to last and one that may not based on its construction. For now, I will pause and leave you to ponder this illustration. We’ll come back to it.

You Can’t Judge a Book by the Cover

Part Two

In Part One I suggested that looks can be deceiving to the untrained eye when it comes to judging which copy of a book has better odds of long-term survival. And I promised to share what book conservators know about how books are made, and how and why they fall apart. So now we are going to look under the hood (the covers, that is).

First, we have to talk about paper.

Way back when, before the Industrial Revolution, paper didn’t grow on trees. It was made out of fibers from cotton and linen clothing and other rags.

But the increased demand for paper in the nineteenth century led to rag shortages, so in the 1840s papermakers began switching to wood pulp. Unfortunately wood-pulp paper becomes acidic, weak, and brittle over time, whereas older paper made from cotton or linen fibers has remained strong and flexible for centuries. By the 1980s, with the problem now quite evident in library stacks, papermakers began converting to making acid-free paper. But between the 1840s and the 1980s millions of books were produced. And libraries have lots and lots and lots of them.

So the condition of the paper is a big factor for long-term survival.

But now you are thinking that books published at the same time are likely to have the same kind of paper, right? And you would be correct. So this doesn’t help a lot by itself when comparing copies. But it is often a combination of factors, including paper strength, that leads to a book’s demise.

Binding

An essential thing that makes a book a book is that the pages are joined, or bound, together along one edge in some way. There are numerous ways this can be done. And the way a book is bound often does vary from one copy to the next. The main reason for this is that older books in libraries are likely to have been rebound at some point. And some of the rebinding methods used in the past were, shall we say, better than others. Also, wear and tear often varies from one copy to the next.

Openability

A simple but important feature to look for is openability — whether a book lies open on the table by itself, or if you have to hold it open. The way the pages are joined together largely dictates this. Openability is important, not only because those that don’t open well are less convenient to use — although they are — but because a restricted opening is one sign of a binding method that makes future repairs difficult or impossible. (Sometimes the thickness of the paper, or the direction of the paper grain also come into play.)

The openability of the most common binding, or “leaf attachment,” methods found in library collections are illustrated below. Restrictive bindings — those that do not open easily — put stress on the pages. Books that open easily allow the pages to move freely. A book with brittle paper and poor openability is likely to end up broken and sad. And difficult to save. But when a book is bound in a flexible manner, there’s hope, and the chances are better that it can be repaired.

Identifying Leaf Attachment Methods

Below are descriptions of the leaf attachment methods most prevalent in library collections, along with illustrations to help you know what to look for to tell one from another.

Sewing Through the Fold (5c above) is a traditional method of joining the leaves of a book together to form a text block, and has been in use since as early as the 2nd century AD. So it’s kind of time tested.

Sheets of paper (folios) are folded together in groups (called signatures, sections, gatherings, or quires).

and the groups are sewn one to the next with needle and thread.

Sewing through the folds is still the way that lots of books are made. Attaching the pages together through the folds makes a book that opens well, is flexible, and allows for future repairs. There is not a lot of stress on the pages, and that is helpful if and when the paper becomes brittle and weak.

Sewing through the folds can be found in paperbacks as well as hardcovers. Look for even stitches in the center folds and a scallop pattern at the top or bottom edge of the book.

Adhesive binding (5d) joins single leaves (rather than folded sheets) together with glue and results in good openability, because the pages are attached only by their very, very edges. As long as there are adequate margins, adhesive bindings usually can be rebound.

Burst binding is a variation of adhesive binding, but it’s a tricky one. They can be confusing to distinguish from a book sewn through the folds. The top edge has the scalloped edge like a book in signatures sewn through the fold. That is because it is in signatures. It’s just that instead of the signatures being sewn, slots are cut through the folds and adhesive is forced (or burst) through to hold the signatures together. When you look closely at a burst binding you will not see any threads. These usually can be rebound adhesively after cutting off the folds.

Most mass market paperbacks are made with poor-quality adhesives that dry up and cause pages to fall out or the text block to split, as shown below. But if the inner margin is wide enough, these can usually be rebound with a better adhesive, as only a tiny amount of the page edges need to be trimmed away.

Double-fan adhesive binding, which uses a high-quality, long-lasting adhesive, is done by commercial library binders and in book conservation labs. The pages are clamped in a press, fanned out, and adhesive is applied. Then the pages are fanned the other way and more adhesive is applied. This deposits adhesive on both sides of the pages (1/16 inch or less). This type of adhesive binding holds up well in most books, but does not work as well on books with thick, stiff pages.

Oversewing (5b), the most restrictive leaf attachment method, was used liberally until about 1985 by commercial library binders. Many books that were sewn through the folds originally were rebound later by oversewing, which requires chopping off the folds and some of the inner margin to make a stack of single sheets. Oversewing was also used to bind together the issues that make up journal volumes. Since the mid-1980s, oversewing has largely been replaced by double-fan adhesive binding.

To oversew a book, the folds are chopped off (if present) and a few pages are put into an industrial machine that has a row of threaded needles. The needles and threads pierce through the page edges many, many times. Then another clump of pages is added, and the machine sews through them and interlocks the stitching with the one before.

An oversewn book with flexible paper is probably going to last a long time, but if the paper is brittle, there will be a lot of page breakage, and you may not be able to put Humpty Dumpty together again.

Below is an oversewn book taken apart, page by page, snip by snip with fine scissors and tweezers. There is so much strong thread that it can take hours to take apart one volume. The resulting pages look similar to those torn out of a spiral-bound notebook.

Besides the restricted opening, another way to tell that a book is oversewn without taking it apart is to look for the close, irregular stitches in the inner margin. This is often visible in older books as they start to weaken.

Also, almost all oversewn books have plain buckram cloth covers.

Because oversewn books are made up of single sheets, rather than folded signatures, you won’t see a scallop pattern at the top or bottom as you do with books sewn through the folds.

Hand-oversewn books are less common, but sometimes repairs were done by a kind of oversewing. The most likely hand oversewing you would encounter is at the front of a book (where damage most often occurs first). Hand oversewing is also called whip stitching or overcasting. This type of oversewing restricts opening, but is not as damaging as machine oversewing because the folds are usually retained, there are not nearly as many stitches, and the stitches are much easier to remove.

Side sewing (5a) is another restrictive binding method. It can be sewn by machine or by hand. All the pages are sewn in one long row of even stitches. The stitches can be removed, allowing for rebinding. This can be a bit time consuming, but it can be done.

Japanese stab-sewn books are usually made with thin flexible paper and adequate inner margins.

Side stapled books are similarly restricted in opening, but they are usually easier to take apart to repair or rebind. Side sewing and side stapling are usually done on thin books or pamphlets made up of single sheets of paper, but sometimes books made from folded pages have been side sewn or stapled.

Pamphlet binding is a single signature of pages sewn together through the fold, often together with a simple cover. Like a book with multiple signatures sewn through the folds, this is a flexible leaf attachment method that can be repaired or rebound very easily. Pamphlets, musical scores, popular journals, ephemera and other short works are often made up of a single signature stapled through the center. Staples can be replaced by sewing to improve durability.

So, yes, it’s complicated, but at least now you know – you can’t judge a book by the cover.

For more information on book structures not covered here, see:

University of Illinois. Preservation Self-Assessment Program. Collection ID Guide. Book and Paper, Binding Types

and for an excellent analysis of the many factors involved in withdrawing copies, see:

Considering Sameness of Monographic Holdings in Shared Print Retention Decisions.