Using the right needle will make sewing easy and more successful. Needles should be as small in diameter as possible, have a blunt point, and have an eye no larger than the shaft of the needle. If the sewing needle is much bigger than the thread used, it will make a hole that the sewing thread cannot fill up. Take some thread (see separate post on thread sizes) with you when you are purchasing your needles so you can be sure of the sizing.
Leather harness called Egg Eye needles (#4) work very well with most thread and are available in leather shops.
Books are traditionally sewn with linen thread which is very strong and can be purchased in several sizes.
Choosing the right thread is important for a successful repair. Using thread that is too thick can damage a book because the text block may not fit back in the original case. Thread that is too thin can tear through the folded signature paper. In general, it’s best to use as thin a thread as possible, but choosing the right thread depends on the kind of paper and how many signatures are being resewn.
LINEN THREAD SIZES Common sizes of linen thread are 12/4,18/3,25/3,35/3 and 60/3. The first number is the thickness of the strand or ply and the second number is the number of strands or ply per thread. So 12/4 is composed of 4 strands that are 12 thick. The 12 refers to an industry designation that relates to the weight of the wholesale quantities of thread. In this sizing system, the smaller the number, the thicker the thread so 12 thread is thicker than 60 thread. 35/3,30/5, and 18/3 are a good assortment of threads to have on hand. It can be hard to recognize a particular thread size so it’s a good idea to mark the size of thread on the inner cardboard spool before discarding the paper wrapper.
Many books are repaired with clear plastic tape or “sticky tape”. What appears to be a quick solution can become a long term headache. Before using plastic tape, it is important to understand how it works and how it affects books.
Plastic tape is dangerous to use in books because it is unstable and causes a great deal of damage. Often two or three layers of tape will cover a single repair. The first repair did not work and additional layers of tape were added to correct the problem. Unfortunately, adding more layers of tape only creates a thick pile of tape; it does not repair the book. Plastic tape has two main parts: a clear plastic carrier and an adhesive that sticks to the paper. As the tape ages in a book, the adhesive penetrates the paper fibers of the page and causes a chemical reaction that stains the paper and makes it brittle. Once the adhesive has dried, the plastic carrier falls away and the stain remains. The adhesive on the tape seeps out the edge of the plastic carrier, attracting dirt or sticking one page to another. Once plastic tape is in a book it is very difficult, if not impossible to remove. Simply lifting the tape off the page will damage the paper because the top layer of paper is removed with the tape. If the tape covers the text, it cannot be removed without damaging the print. Removing plastic tape is difficult even for trained conservators who work with chemicals and special tools.
Using plastic tape to reattach a loose page restricts the page from turning freely. The plastic tape has a sharp edge and makes the original paper heavier than before so the paper tends to turn against the edge of the tape and not at the hinge. Soon the paper breaks against the edge of the tape and falls out of the book. Now a second repair is needed and if the page is repaired a second time with plastic tape, the same problem occurs.
Wide, clear plastic tape is also used to repair the cover spine or corners of a book and special “repair wings” are sold to repair corners as well. While tape covers up the problem it does not repair it. Often the tape slides out of position or detaches entirely while the adhesive remains on the book cover attracting dirt or sticking books to one another on the shelf.
Decisions regarding when and how to use clear plastic tape should be made ahead of time. Be certain a book is not important to keep before repairing it with plastic tape. Keep in mind that once the tape is in the book, it cannot usually be removed without damaging the book.
Document repair tapes differ from common clear plastic in several ways. The carrier (the part of the tape that holds the adhesive) is thin, acid-free paper, not plastic. It is not as stiff as plastic tape so a page can turn and bend more easily. The adhesive used is a neutral acrylic adhesive that should not dry up, yellow over time or seep out the edges of the document repair tape. Because this adhesive is neutral (neither’ acidic nor alkaline), it should not react chemically with the paper.
The manufacturers of these tapes have tested the materials using artificial aging tests and they believe these tapes will remain stable over time and can be removed easily. Actual experience is not always so positive. Some libraries are finding that these tapes dry hard and crack or that the adhesive dries up and the paper carrier falls off leaving the paper discolored. Because of these problems, document repair tapes should not be used on valuable books. Document repair tape has become accepted for use as a quick way to repair paper tears and is definitely better than clear plastic tape.
Heat set tissue is a thin tissue that has been coated with a heat activated, acrylic adhesive. The tissue is torn or cut to fit the tear or paper loss, laid in position and covered with silicone release paper (so the tissue doesn’t stick to the hot iron). The tissue is adhered to the paper with a heated iron (approximately 100 degrees F.). A standard household iron or tacking iron from a hobby store can be used to adhere heat set tissue. It is sold with the silicone release paper.
Heat-set tissue tends to be more brittle than Japanese repair tissue as it does not have the long, strong fibers of the Japanese tissue. It is not recommended for use on the folds in paper or areas that need to flex and bend. Since heat-set tissue is not applied with moisture, it works quite well on shiny, coated paper that can buckle when wet (as might happen with glue or paste).
Japanese repair tissue is sometimes called “rice” paper, but this thin paper is made from the fibers of the mulberry tree, not from rice as the nickname implies. The strength of Japanesere pair tissue comes from its long fibers which make the paper very strong, even though it is very thin. Handmade Japanese repair tissues are made on a mold and have mold or “chain” lines which can be seen in the paper. These lines generally run the same direction as the paper grain. The lines are visible when the paper held up to a light or held down to let the light shine from above. The grain can also be determined by using the tear, bend or water test discussed previously. In general, Japanese repair tissue is torn rather than cut. A piece of torn Japanese tissue has a delicate feathered edge that blends into the repaired paper, so there is no sharp edge for the repaired page to turn against. Different methods of tearing Japanese tissue are outlined in a separate post.. Japanese repair tissue can be purchased in different weights and colors. Generally, three weights will cover most repair needs. Since most paper is not truly white, I recommend you buy the “natural” or “toned” colors.
TENGUJO light weight for working over type or illustrations
KIZUKISHI medium weight for most repairs
SEKISHU heavy weight for heavier paper
Although Japanese repair tissue may seem very expensive, only a small amount is used on any one tear. One sheet of Japanese repair tissue will last you a long time.
Book Paper and Book Cloth Many types of paper or book cloth can be used in manufacturing, binding and repairing a book.
BOOK PAPER Although many different types of papers are used to print and manufacture books, three important types of paper to be familiar with in book repair are uncoated paper, coated paper and acid-free paper. Uncoated paper is the most common type of paper and is made from plant or tree fibers that are processed into sheets. Originally, most uncoated paper was handmade from linen or cotton rags. These older papers age very well because they contain few damaging chemicals. In the 1860s, a process was developed to turn cellulose fiber from trees into paper. This type of paper can be made in large quantities but contains some very damaging chemicals that cause paper to become brittle more quickly than paper made from cotton or linen. Coated paper – A sheet of paper can be impregnated with very fine clay to produce a very fine printing surface. Introduced at the end of the 19th century, coated paper is ideal for printing halftone illustrations. Unfortunately it is not very strong and is highly susceptible to water damage. Often the text pages of a book are printed on uncoated paper while the pages that contain illustrations are printed on coated paper. The coated paper may be part of the signature or tipped onto a page of uncoated paper. Acid-free is a designation given to paper that has a pH value of 7.0 or greater on a scale of 1 to 14. Fibers from any source can be made into paper that is acid-free. Both coated and uncoated papers can be acid-free. The common types of acid-free paper used in book repair are photocopy paper and Japanese repair tissue.
BOOK CLOTH Book cloth is a specially woven cloth backed with thin paper. The paper backing gives the cloth support, minimizes stretching and allows the material to maintain a crease. There are three main categories of book cloth:- Starch-filled book cloth in which the weave of the cloth is filled with starch. This type of cloth is sometimes called sized book cloth. Heavier book cloth is sometimes called buckram. Acrylic, pryoxylin, or vinyl impregnated book cloth. Plastic coated book cloth.
Paper and book cloth have a grain just as fabric does and it is important to understand how that grain affects repairs. When the grain of the paper and book cloth runs parallel to the spine of the book, the cover and pages open freely and stay open without much effort. This is called “with the grain”. Paper that is bound into a book with the grain running perpendicular to the spine of the book is called “against the grain”. Modern publishers often print the pages of a book against the grain to get more pages on a large sheet of paper. When the grain runs perpendicular to the spine of a book, the book can be difficult to open and it will not remain open without a great deal of pressure. Books printed against the grain are easily damaged since patrons must force the book open to read or photocopy it. When pages or the case of a book are repaired, the grain of the repair materials should always run parallel to the spine of the book.
These two posts should give you a better understanding of how a book is constructed so that when you begin your repair work you know exactly what parts you need to work on first.
Books are constructed in several ways. Many repair materials work best on certain kinds of paper or in specific parts of a book. “The right tool for the right job” is an axiom that applies to book binding as well as other fields. Having a few specialized tools and understanding how to use them will save you time and energy. Here are some of the parts of a book you may get very familiar with when you start doing your own book repairs.
Text block – The pages of a book, whether they are sewn or glued together, are called the text block. Case – The covers of a book are called the case. The case is made of the front cover, the spine and the back cover. Signatures – When the text block is sewn, the pages are gathered together in groups; then each group is folded in half. A group of folded pages is called a section or signature and is usually four to eight pieces of paper (four pieces of folded paper equals sixteen numbered pages).Books that are constructed of sewn signatures tend to function best because the pages are securely attached to one another and they open flat. Modern manufacturing techniques enable book manufacturers to create a text block with signatures, cut small notches in the folded edge and insert glue to hold the pages together instead of sewing thread. These books look like they are sewn, but they are not. Open the text block to the center of a signature and look for the thread, if it’s not there, the book is glued.
Text blocks in loose sheets – Text blocks can also be single sheets glued together in a process called adhesive, perfect, or fan binding. In this process, fast drying glue is applied to the spine of the text block. Adhesives that dry very quickly are often brittle and that is why the spine of a book cracks when the book is opened. Once the spine glue is cracked, the pages will begin to fall out. In addition to the problem of brittle glue, there is often very little glue attaching each page to the adjoining pages. When the glue is only in contact with the very thin edge of each sheet of paper, pages can easily separate over time.
Single and double fan binding – ln single-fan binding, the pages of the text block are fanned in one direction and glued along that fanned edge. ln this style of binding, a thin line of glue penetrates the inner margin of each page, not just the spine edge.
Double-fan adhesive binding goes another step beyond single-fan binding. After the pages are fanned in one direction and glued, they are also fanned in the opposite direction and glued along the second fanned edge. Double-fan binding applies glue on the inner margin of each side of the page, not just on the spine edge or the inner margin of one side of the paper. It is much stronger than single-fan binding. When professional binders bind a book using double fan binding, they use adhesives that dry slowly and are flexible. In addition, they usually reinforce the spine edge of the adhesive bound text block with cloth and paper so it is stronger and the text block opens flat. Oversewn text blocks – Before craftsmen began to fan bind books, the most common form of binding was oversewing. In the oversewing process, the folds of the signatures are trimmed off and the pages of the text block are oversewn to one another with a diagonal whip stitch. Since the sewing threads tend to pierce deep into the inner margin, the pages are restricted from turning easily. Oversewing is a strong form of binding, but it is often so strong that over time the pages can break out of the binding as they are forced to turn against the sewing threads. Oversewn books may not be candidates for rebinding since much of the inner margin was trimmed off or damaged by the oversewing threads. Books should not be oversewn unless they are very heavy and have wide gutter margins to accommodate the sewing threads. Flat back text blocks – Flat back books are a type of binding which has a flat text block spine. The case spine of flat back books is usually a piece of book board covered with book cloth. The spines of flat back text blocks have a tendency to become concave over time. To prevent this, the spine of the text block can be rounded and backed. Rounded and Backed Text Blocks -Text blocks are rounded and backed to shape the flat spine of a text block into a curved spine with shoulders. Rounding a text block is the process of molding the spine of a text block into an arc of approximately one third of a circle. Rounding takes place after the pages of the text block are attached to one another by sewing or gluing. A light coat of adhesive is applied to the spine which is then worked into shape with light pressure applied with your fingers or a special hammer called a backing hammer. Backing is the process of shaping a ridge or shoulder on each side of the spine of a text block prior to attaching the spine lining material. Using a backing hammer, the folds of each signature or glued pages are bent over from the center to the left and right until shoulders are formed against which the boards will fit. The width of the shoulders is determined by the thickness of the cover boards. In addition to providing space for the cover boards, backing also distributes the swell caused by the sewing threads or adhesive and helps maintain the round of the text block over time. Book case construction – Regardless of how the text block is assembled, modern books are usually manufactured in two stages. The text block is constructed in one operation where the pages are attached to one another, the spine covered with a cloth liner, called crash, and a paper spine liner is added over that. The book case, consisting of a front cover, a spine and a back cover, is constructed separately in a second operation and the two parts of the book are attached by gluing the crash and end papers to the case covers. The crash holds the text block into the case while the end papers cover up the crash.
