common problems
The survival of anything made of paper depends on the properties of the paper itself, the materials applied to it, and the effect they have on each other. Unlike materials such as textiles, where older pieces tend to be more fragile than new ones, the opposite is often the case with paper. If stored in a good environment, paper made in Europe from the late medieval period to the mid-19th century tends to be in good condition. however, paper made after the mid-19th century may be affected by the poor quality of the materials from which it was made. therefore, some modern papers only have a shelf life of a few decades.
From the mid-nineteenth century onward, the growing demand for reading material coincided with the development of papermaking and mechanized printing. this allowed the widespread use of cheap and abundant wood pulp as a raw material for making paper. wood pulp can simply be shredded and then turned into paper. This type of pulp, known as groundwood, contains all of the acidic components that are present in wood. paper made from ground wood pulp, e.g. newspaper, cheap to produce but inherently very acidic.
You are reading: What is foxing in books
types of paper
Paper has been used to create fine art and literature since it was invented in China more than 2,000 years ago. Paper is made from a variety of natural materials that vary by country and culture of origin, such as Japan, China, and India. Within the European tradition there are two basic categories: handmade and machine-made paper. even so, there is a great variety in weight, texture and color. Documents and works of art on paper are composed of both the paper and the ink, paint, or other decoration applied.
Earliest European paper was made by hand from plant fibers, usually recycled linen or cotton rags. these were crushed, soaked and macerated to separate the fibers, producing a watery pulp that was filtered through mesh molds to make sheets of paper. the paper produced in this way is highly absorbent and acts as a blotter. it can be difficult to produce crisp lines or clear text because wet ink or paint runs and spreads.
To prevent ink from absorbing, the surface of the paper is “sized”. the term sizing was borrowed from artists, who pretreated wood paneling and canvas with diluted glue, called sizing, to seal the surface. The first paper sizing involved dipping the paper in diluted gelatin to give it a harder, less absorbent and more resistant surface. Alum (potassium aluminum sulfate) was added to the gelatin to help adhere it to the paper and to retard mold growth. Handmade paper made from linen or cotton has long fibers that make it more resistant. furthermore, this type of alum glue is usually chemically stable.
acidity
Acidity is one of the most important causes of paper damage, as it weakens and eventually destroys the fibers that make it up. As a result, paper made from shredded wood pulp quickly breaks down from the inside. the first sign of this is the paper turning yellow, then brown, and increasingly brittle. For example, newspapers are made from ground wood pulp, and the acids in the paper cause it to discolor and become brittle. decomposition of newspaper from within is accelerated by exposure to light and/or high humidity. Wood pulp can be chemically treated to remove acids and impurities. paper made from purified wood pulp is more expensive but lasts longer than paper made from ground wood pulp. however, in the past, its shelf life was still limited because it was almost always treated with alum rosin glue.
Alum rosin size was introduced in the mid-19th century, along with wood pulp. it was made from a mixture of alum, in this case aluminum sulfate, and rosin, the resinous material left over when turpentine is distilled. This type of alum is different from the previous type and is not chemically stable. alum rosin size was cheap, could be added while making the paper rather than as a separate stage, and produced an excellent surface for printing. Unfortunately, in humid conditions it generates sulfuric acid, which attacks the paper, turning it yellow and making it very brittle.
ink
another problem that can damage paper (usually in books, drawings and letters) is caused by the type of ink used. Iron gall ink, made from tannin (galls), vitriol (iron sulfate), gum arabic, and water, was used in Europe from the late 12th century. depending on how the ink was originally made, iron gall ink can ‘burn’ holes through it. a similar problem occurs with verdigris, a green pigment made from copper, which was often used in older Islamic books as a green border around text.
The first indication of iron gall damage is a brown halo around the ink lines. it gets worse in wet conditions, and while dry conditions will slow the process, they can’t prevent it.
fox
The term ‘foxing’ describes small yellowish-brown spots or specks on paper. Two main causes are mold and iron contaminants in the paper. Molds feed on the paper itself, as well as any dirt or organic material on it, such as finger marks, food stains, and crushed insects. Tiny metallic impurities can be found in the paper as a result of the original manufacturing process or from dirt and contamination. Wet conditions encourage mold growth and cause iron contaminants to rust. in some cases, a conservator can reduce the disfiguring effect of foxing, but in many cases they simply have to accept this old damage.
First decide if your paper and books have historical, aesthetic, or sentimental value. If you think they have significant monetary value, consider professionally valuing, insuring, and preserving them.
The cost of neglect and shoddy repairs is high. Because books are often not decorative objects in their own right, and therefore are not displayed, there is often a resistance to the cost of professional conservation. you need to balance this against the monetary and sentimental value of your books.
book handling
never remove a book from a shelf by putting your finger on the top of the spine and pulling the book toward you; this damages the top cap, which will eventually break. try removing a book by running your hand across the top and gently pushing from the leading edge or pushing the side books further forward so you can wrap your hand around the spine of the book and firmly grip each side. be sure to hold heavy books with your other hand underneath.
caring for pocket books
The most common type of binding in modern homes is called a “perfect” binding and is used for magazines and newspapers, modern paperbacks, and some modern hardcover books. Both the cover and the pages are glued on the edge of the spine with a thick layer of hot glue. this is the cheapest type of binding and is intended for the disposable market. it is often combined with the use of poor quality acid paper.
Once the adhesive along the spine dries or breaks, the pages begin to fall off. you can put the book in a book box and store it. this will at least keep the parts together and minimize further damage. if the book has value, a professional conservator may be able to repair and rebind it.
family bibles
Large family bibles are especially vulnerable to damage from improper reading, handling, and storage. often the structure is not strong enough to support the weight of the text block and boards. Also, the older the volume, the more likely the binding will become damaged and brittle, so it is important to support the entire structure and weight of the book when you pick it up and while you read it. foam wedges are the best solution.
typical damage caused by an opening without support
Opening a book flat on a table puts stress on the weakest point in the binding, the juncture between the spine and the front and back boards. once these seams break, the covers and spine can rip, the stitching can rip, the text block can split, and the pages begin to fall out. if left untreated, the book will eventually be destroyed.
Normal photocopiers require the books to lay flat on the glass base. this damages the seam, the spine and the joints. Libraries often have special copiers that allow you to photocopy a page without forcing the layout of the book: if you have to photocopy, use one of these.
use of foam wedges for large books
Foam wedges fully support the boards up to the joint with the spine. this means that almost all of the weight of the book is supported by the foam wedges, not the spine and hinges. they also restrict the opening of the book and prevent you from accidentally tearing the spine by forcing pages too flat. snakes (curtain weights: a small chain of lead weights sewn to a tube of fabric) can be placed on the pages to hold them open without damaging the spine (suppliers: conservation team or conservation by design).
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The use of the foam wedges depends on whether you are at the beginning, middle, or end of the book, as the shape of the spine changes as you read. use additional flat foam blocks to hold the book in its natural shape if it is opened toward the beginning or end. alternatively, you can roll up clean, dry hand towels to hold a book without foam wedges.
In modern hardcovers and older books, especially large books, the tables are larger than the text block. when stored upright on a shelf, the text block is unsupported and will slowly ‘fall’ towards the shelf. Initially, this process distorts the spine: the top of the spine is flattened, the bottom of the spine is pushed outward, and eventually the joints between the boards and the spine begin to tear. This damage can be prevented by storing the book horizontally or, if upright, inside a book “shoe.”
book shoes are custom made by conservators to fit an individual book. they are made from archival material and incorporate a text block support to compensate for the space between the text block and the shelf. Slipcovers, which are like a book shoe but locked in at the top, are not recommended because they make it difficult to remove the book without pulling on the seam and do not support the text block.
packaging and storage of books
Avoid storing books in attics and basements and keep boxes slightly off the floor and walls. this prevents minor flood damage and the airflow will help prevent insect and mold damage.
When packing books in storage boxes, make sure the spine is supported; otherwise, the tables, spine, and text block may be separated. lay the books flat, spine inverted, with the largest on the bottom and the smallest on top, making sure there aren’t too many in a stack, or pack spine side down with similar sized books together. do not stack books on top of any extra space.
Archive-quality, individual permanent boxes are the best choice for medium- and long-term storage of valuable books, rare items, parchment text blocks and parchment-covered books, leather-bound volumes, and accessorized books. Although expensive, the box should fit the book exactly and help protect it from damage by light, heat, moisture, and contamination. Phase Boxes are individually made to order from archival quality cardboard. they are the most economical way to keep the books you value in good condition. they can be good for books that have accessories like metal clasps or decoration that would otherwise rub or snag on neighboring books.
die-cut boxes are commercially manufactured, come in standard sizes (which may not fit your book exactly), and are delivered flat packed. They are made from archival quality folding cardboard and can be useful for magazines and comics. however, some sizes can only be purchased in bulk.
Four-flap enclosures are a cheaper and simpler method of protecting small books, paper brochures and booklets, etc. that are vulnerable or have loose pages. these can be made simply with an archival quality manila or kraft paper or thin card like the wrappers below.
wrapping is the cheapest option; It acts as a dust jacket and is a good choice for damaged books, e.g. if the covers or pages are loose or if the bookcase is exposed to direct sunlight. wrap a book in a sheet of thick, archival-quality paper or thin cardstock, such as kraft (120 g/m²), manila (225 g/m²), or cover paper (300 g/m²), depending on the size from the book. choose paper that is lignin-free, acidic, buffered, and has a pH of 7-8.5.
When the boards have come loose and none of the above is possible, you can use flax tape to reattach the boards to prevent damage to the text block.
leather bindings
the leather has been chemically processed (tanned) so that it does not rot when wet. alum-tanned leather has only been partially tanned by treating (tanning) with alum. Under the right conditions, it is very strong and durable. however, if it gets damp or wet, it will deteriorate and become damaged. Untanned leather, such as parchment or vellum, that has been limed, stretched, and dried, can also be strong and durable. however, if it gets wet it will shrink and start to rot.
avoid using leather coverings on books. it doesn’t help preserve leather and can actually be very damaging, especially when too much has been applied.
dealing with red rot
This describes leather that appears dusty, orange-red, and brittle. this is caused by a combination of the original tanning method (vegetable tanning) and contamination. sulfur dioxide contamination reacts to form sulfuric acid which attacks the leather from within. once the damage has been done, the only thing you can do is try to limit the damage caused by handling.
You may want to pack or wrap the book in materials that absorb the acids emitted from deteriorated leather. using leather coating or other materials like Vaseline won’t help (and may cause more damage) because the problem isn’t on the surface but deep within the leather.
regular book maintenance
Pulling books off the shelves once or twice a year to dust them will keep them clean and is a good way to spot mold or bug problems before they get too damaged. set up a table with some clean paper, outside if it’s a warm, dry day. take each book in turn, hold it firmly closed by the leading edge, and using a soft-bristled brush, such as an old-fashioned bristle shaving brush, gently brush away any dust.
work from the edge of the spine to the front edge, otherwise you will end up pushing the powder down the spine. avoid using a vacuum cleaner because of the risk of sucking up any loose debris. this method is not suitable if the pages are severely distorted, wrinkled, or damaged because dust may enter the pages. vacuum or wipe down shelves before replacing books.
if the paper is in good condition, it is possible to remove dust and dirt from the page margins with a chemical sponge, also known as a chemical or fume sponge (suppliers: preservation by design or preservation equipment). these are made from vulcanized rubber and must be used dry, no liquid is required. They work by trapping dirt on the surface of the sponge. when this happens, simply cut away the dirty surface to expose the clean sponge. a chemical sponge won’t remove damage from mildew, stains, or stains, and it’s not a good idea if the paper is brittle or torn, or if the surface of the paper looks “spongy.”
Clean only the margins and be careful not to clean printed areas or illustrations as this may smear or remove ink. Leave annotations, notes, and doodles in the margin, as these can be historical evidence that adds monetary value and interest to your book. It is important to wash and dry your hands regularly while cleaning, otherwise you will transfer more dirt than you will remove. Cut a small piece of the chemical sponge, about 25 x 25 x 10 mm. apply it very lightly on the dirty area of the margin.
If a chemical sponge does not remove the dirt, you can consult a conservator. if pieces of paper are removed, stop immediately. if you find pieces of paper in the book, you should put them in an envelope with a note saying where the piece was found in the book.
clean moldy books
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Mold growth is caused by high relative humidity, or humidity, combined with poor air circulation. When it comes to caring for your antiques, it’s the relative humidity that matters. Relative humidity measures how much moisture is in the air relative to the maximum amount of moisture the air could hold at that temperature. if conditions become drier and the relative humidity drops below 70%, the mold will go dormant, but will reactivate again if the relative humidity rises.
If you have moldy books, try to locate the source of the moisture, e.g. leaks or books against a cold exterior wall and address the underlying cause of your problem. Assess whether the mold is active or dormant by carefully testing it with a fine brush. if the mold is dry and powdery, it’s probably dormant, while if it’s smooth and blotchy, it’s probably active. if mold is active, move books to a warm, dry area until it goes dormant.
To remove mildew, take the book(s) outside on a warm, dry day. hold each book so that it remains firmly closed, to prevent contamination of the text block, and clean as described above. clean shelving area thoroughly with a commercial fungicide or 5-10% bleach solution, wipe/rinse shelving with water to ensure all bleach residue is removed, and allow to dry before replacing books .
what not to do…
don’t use old-fashioned cleaning remedies bread is a traditional dry cleaning material used to remove dirt from paper. if you rub a piece of fresh white bread between your fingers, you will find that it is quite effective at picking up dirt. the slight stickiness of the bread is why it works and also why it can be a problem. it can leave a sticky residue that will attract more dirt. oily residue or small crumbs trapped in the paper fibers will encourage mold growth and encourage pest attack.
Don’t trim documents or drawings to fit a frame In the past, paper artwork was sometimes trimmed to fit a frame, mount, or album. this can be done by some commercial fitters today. however, it is important not to crop documents or artwork because you can accidentally remove important historical evidence such as signatures, margins, and plate marks, which add to the provenance and value of the piece.
do not laminate paper plastification is used to reinforce paper by sealing it between sheets of plastic, using heat and pressure. while it is fine for disposable papers that are handled a lot, it is not appropriate for historical or valuable papers. Unfortunately, the plastics used are chemically unstable and turn yellow and brittle over time, producing acids that attack paper, ink, and pigments. lamination is irreversible because the heat and pressure cause the plastic to stick completely to the paper, so if you value your paper, don’t laminate it.
don’t use pressure-sensitive tape for repairs one of the worst things you can do to paper is try to repair tears with pressure-sensitive tape, like duct tape, plastic with adhesive backing or tape. these are usually made of a thin, flexible backing, combined with an adhesive that is tacky at room temperature.
In the short term, removing the pressure sensitive tape can remove the top layer of paper fibers. in the medium term, the support falls off, while the adhesive left on the paper attracts dirt and can adhere to and damage other papers placed next to it. in the long term, the adhesive can seep into the paper and leave an irreversible yellow or brown discoloration. if the adhesive becomes acidic over time, it will also attack the paper.
avoid using tape on the back of the paper, for example when making homemade mounts. in the long run, the tape’s adhesive can creep through the paper and produce irreversible patches of discoloration on the face.
Modern pressure sensitive tapes use an acrylic adhesive. these don’t fade too much and don’t soak into the paper as they age, although they can soak up a bit depending on how porous the paper is. however, they cannot be dissolved in water or solvents, and often cannot be removed without damaging the paper.
“Archival quality” pressure sensitive tapes are also available. they can be described as chemically stable, non-yellowing, acid-free, or removable with solvents or water. just because they are ‘archival’ doesn’t mean you can use them on your valuable artwork or documents. adhesive residue can be difficult or impossible to remove. also, it may not be possible to use water or thinner without damaging the paper. reversibility is not just about a material, but also about what it is applied to. tapes that use a water-soluble starch adhesive are available and are a better alternative.
It is best not to use any type of pressure sensitive tape.
Modern household adhesives such as uhu, superglue, blutack, copydex, pritstick and rubber cement glues are not suitable for value paper. the adhesive will fail in the long run and as the products break down they will stain and damage the paper itself. It can be difficult to remove glue that has dried and becomes dark and brittle.
do not use tape to encapsulate paper, encapsulation is sometimes recommended as an alternative to heat seal lamination. the paper is placed between two sheets of chemically inert plastic, which are held together with double-sided tape around the edges, but not in contact with the paper. the paper is held in place by the electrostatic charge of the plastic.
The main problem with this is the use of double-sided tape, which tends to have a very strong adhesive. if you accidentally touch the paper with the tape, there is no ‘forgiveness’. if removed, the tape will take away the top layer of paper, ink, or paint. accidental contact can occur if there is a slight movement of the paper when it is encapsulated, or when the plastic sheets are pulled apart to remove the paper. a good alternative is to enclose paper between proprietary sleeves that are heat-sealed on two or three sides.
do not dry mount this is a technique used to mount photos, papers and posters, especially if they also need to be flattened. dry mounting uses thin paper that has been impregnated with adhesive. the tissue is placed between the back of the paper to be mounted and its supporting paper or board. Heat and pressure are used to melt the adhesive into the fabric, bonding the paper to the backing. As always, problems and damage are likely as the adhesive ages; dry mounting is a very difficult process to reverse.
don’t use paperclips, staples or sticky notes, they are all meant for disposable office paperwork. they are not suitable for temporary or permanent use on valuable paper or artwork. metal clips and staples will corrode and leave rust spots on the paper. paper clips often tear paper when removed and can leave a permanent distortion in the paper. Post-it notes leave a residue. colored folders or tape can stain paper in wet conditions, while rubber bands cut through paper when new and then become sticky as they age and wear off.
If you find any of these in your old papers, carefully remove them. if you think they are of interest, keep them separately, for example, you could take a picture of a document bound with colored tape, and then keep a colored tape in a page protector next to the original letters.
produced by paper, book & conservation of paintings section, v&a
See Also: Stephanie Bond – Book Series In Order