April 2013 – How To Repair Your Favourite Books

Wheat Paste Recipes

Over the years I have been asked for (and tried) many variations of recipes for wheat paste. Here are three that have always been successful.

Thick Wheat Paste (general pasting)
6 tablespoons wheat starch
2 cups cold water
Place the wheat starch in the top of a double boiler. Mix the water into the starch stirring constantly. Bring the mixture to a boil.
Lower the heat and stir constantly as the mixture simmers. Cook until mixture thickens.
Remove from heat and cool.
Put through a sieve and store refrigerated for 3 – 4 days.
Thin Wheat Paste (used to thin PVA – see earlier post)
3 l/2 tablespoons wheat starch
2 cups cold water
Follow the instructions for Thick Wheat Paste above.
Microwave Wheat Paste
1 tablespoon wheat starch
5 tablespoons distilled water
Place the wheat starch in a deep container, add distilled water and place in microwave. Microwave on high setting 20 – 30 seconds,
Remove paste and stir. Return to microwave and cook another 20 – 30
seconds. Remove and stir again. Continue this process for 3 – 4 minutes depending on the power of your microwave.

Paste should stand a few minutes before using.

Book Repair Glue

The most commonly used glue for book repair these days is Polyvinyl Acetate (PVA). Also known as craft glue or wood glue, PVA is a good all-around adhesive. It has a low moisture content and dries quickly. It dries flexible, so it can be used to tighten hinges, repair book cover corners and reattach loose book cloth to book board.

Importantly PVA is not affected by mold or fungi. However, it is damaged by freezing, so many US and European book repair supply houses will not sell PVA by mail from October to March. If PVA freezes, it separates and loses its adhesive properties.

PVA can be thinned with water or thin wheat paste for different consistencies and effects.

Thinning PVA with water adds moisture and does not add any additional adhesive properties while thinning with wheat paste adds the adhesive qualities of the paste to the glue.

Many book binders or repair technicians use a 50/50 mixture of PVA and wheat paste strained through a sieve. You may find different adhesives or mixtures of adhesives by further internet research.

PVA glues cover a wide range of brand names and not all are used to repair books. For instance Elmer’s glue is technically a PVA but is not flexible when dry so it has limited use for repairing books. You may decide to have a few brands to cover the different types of repairs you are carrying out on your books.

Book Repair – Glue or Paste?

There are two main kinds of adhesives used in book repair: paste and glue. Each has special properties and should be used in specific instances.
1. BOOK REPAIR PASTE
Paste is generally a cooked mixture of water and vegetable starch, such as wheat or rice.
2. BOOK REPAIR GLUE
Several types of glue have been used in bookbinding over the years, the most common being animal hide glue. In recent years, animal-based glues have been replaced with synthetic vinyl resin glues, the most common of which is polyvinyl acetate emulsion (PVA).

Should I Use Glue or Paste?

Using glue will give you a quicker drying time and a permanent (non reversible) adhesive fix for your book repair. This is a good option for loose pages in a paperback book where the initial adhesive has cracked/dried following years of use. Glue should not damage the pages.

Using paste will take a longer time to dry but will be a stronger fix and the paste will penetrate the fibers of the paper. Paste repairs can usually be reversed if needed but the moisture content of the paste and the longer drying time can buckle the paper pages being repaired.

Most people learning to repair books use too much adhesive. The belief seems to be that if a little is good, a lot is better. In book repair, that just isn’t true. A thin, even coat of adhesive makes the best bond. Too much adhesive will ooze out of the edges of a repair and stick to the pages. Also, too much adhesive causes the paper to wrinkle and takes longer to dry.

Watch each repair carefully. If there is excess glue or paste, wipe it away. Next time, try to use less paste or glue. When applying adhesive, choose a brush that matches the size of the surface. When pasting or gluing a small area, use a small brush. When the area is larger, use a bigger brush.

Book Repair Adhesives

There are two main kinds of adhesives used in book repair: paste and glue. Each has special properties and should be used in specific instances.

1. BOOK REPAIR PASTE
Paste is generally a cooked mixture of water and vegetable starch, such as wheat or rice. Repairing paper with paste will give a stronger bond than repairing it with glue because the paste soaks into the paper fibers and bonds them together. Since paste contains water, it can stretch and cockle paper. It dries slowly and can usually be reversed with water.
2. BOOK REPAIR GLUE
Several types of glue have been used in bookbinding over the years, the most common being animal hide glue. In recent years, animal based glues have been replaced with synthetic vinyl resin glues, the most common of which is polyvinyl acetate emulsion (PVA).

In the next post I’ll cover the way to decide whether you need to use glue or paste for your book repair.

Clear Plastic Tape (Sticky Tape)

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 Tape

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

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

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.

Repairing Paper

In general I use Japanese repair tissue, wheat paste, and heat-set tissue or repair tape to repair paper tears.

Over the next few posts I’ll cover the basic information about:

Japanese repair tissue
heat set tissue
document repair tape
clear plastic tape
repair adhesives
the difference between glue and paste
pva glue
wheat paste (including recipes)

These repair methods will be applicable to any paper tear in a book whether its a paperback or hardcover.

How to Test for Grain in Paper or Book Cloth

All paper and book cloth has a dominate grain. It’s important to know the grain direction before you start your book repair, so here are the most popular methods for determining the dominant grain in either paper or book cloth.

Paper can be tested for grain using the bend test, the tear test or the water test. The grain of book cloth usually runs parallel to the selvage or bound edge of the fabric. If the selvage of the book cloth has been cut off or if there is any doubt about the grain of book cloth, the bend test or the tear test can be used to determine the grain.

Bend Test
The quickest way to test the grain is to bend the paper or cloth slightly in each direction. Bring two opposite edges of a piece of paper or cloth together but do not crease. Instead, gently press down on the bend with minimal pressure. Feel any resistance. Now bring the other two opposite sides of the paper or cloth together and repeat the process.
In one direction there is more resistance than the other. The greater
resistance means the paper or cloth does not want to bend in that direction because it is bending against the grain.
When the paper or cloth is bent in the opposite direction, there is much less resistance. The bend that offers the least resistance is the bend that goes with the grain of the paper or book cloth.
Mark the direction of grain on the paper or book cloth for future reference.
Tear Test
Another way to test for the grain is to tear the paper or cloth. Paper or cloth will tear easily and straight along the direction of the grain. When forced to tear against the grain, the paper or cloth will be difficult to tear and the tear will tend to curve until it meets the grain. Tear the cloth or paper close to a comer and then pencil a small straight line in that corner indicating the direction of the grain so it won’t need to be determined every time it is used.
Water Test
When grain is particularly difficult to find, a water test can be used. Use this test only to test paper being used to repair a volume, not on pages bound in a book. Draw a 4” straight line along one comer of a large sheet of paper. This line will not necessarily be the grain line, it is simply an orientation line. Cut a square out of the comer, including l/2 of the line. Moisten the small square of paper and lay it on a work surface. As the water is absorbed into the paper fibers, the square will begin to curl. The two edges that curl toward one another are parallel with the grain. Mark the correct grain on the square. Replace the curled square in position on the large sheet of paper (match the cut pencil line) and mark the correct grain on the large sheet. Remember, the first pencil line is not necessarily the grain line.