CHAPTER IV
MATERIALS
In a recent pamphlet issued by the Government Printing Office, containing a list of materials and articles used in the printing and binding of public documents, the number of items for binding alone reaches the surprising total of 171. Many of these are materials used in marbling, others indicate slight variations of color and weight in standard leathers and cloths. But exclusive of all these the number of materials called for is over forty.
It is not the writer's purpose to discuss all of these forty or more materials, but it seems necessary to mention that many materials other than those used in covering books (always some kind of cloth or leather) are used in binding. Furthermore, the strength of the book after it is bound will depend almost as much upon the materials used in its inner construction as upon those used in covering it. The inner materials, if not wisely selected as to quality or in reference to the kind of service which the book is to receive, may cause an otherwise excellently bound book to give poor service.
In general, however, a reference to binding materials means those which are used in covering books. It is the cover which renders a book attractive or unattractive, and which contributes more than any other one item, except possibly sewing, to the long life of the book. We should therefore know the initial cost of different covering materials and the length of service which each material will give under different conditions. When they are not imitations we should be able to recognize the best-known materials, either on or off the books. An unscrupulous binder can easily take advantage of ignorance of these matters.
So far as the librarian is concerned only two classes of materials need be considered for the covers of books--leathers and book cloths. This does not indicate a restriction of choice, for when we consider that leather comes from a large number of animals, that there are a great many different kinds of cloth, that cloths and leathers can be obtained in a great variety of colors, there seems to be an embarrassment of riches. As a matter of fact most librarians confine themselves to four kinds of leather and four or five kinds of cloth, each in three or four different shades.
LEATHER
The most expensive materials used in covering books and those which vary most in quality are leathers, the skins of animals which have been tanned and made flexible. The best bookbinding leathers are those which are flexible both in the skin and on books, and the surface of which is not easily damaged by friction. Owing to the many kinds of leathers and their variation in quality, it is difficult to learn to know them well.
The skins of all sorts of animals have been used for covering books. Certain ones, not suitable for library binding, are still used for the purpose in various parts of the country, so that librarians need to become expert in their knowledge of which leathers may be employed and which ought to be rejected.
Variations in the same kinds of leathers are caused by:
(_a_) _Age._ Skins of animals which have not reached full growth should not be used for binding library books. Since they are immature, the fibres have not become tough, and they have not reached their maximum thickness. If the skins which the binder is using are exceptionally small, it is probable that the animals from which they were obtained were too young. On the other hand, the skins of very old animals should not be used, since the fibres of the skins have lost something of their flexibility and strength. They cannot be readily detected, but they are sure to give poor service. As an illustration of the effect which age has upon leather it will be sufficient to note the well-known fact that calf skin is useless for library purposes, while cowhide within certain well-defined limits is exceedingly useful.
(_b_) _The sex of the animal._ It has been proved beyond question that the skin from the female of some animals, notably goats, does not wear as well as that from the male.
(_c_) _Country from which they come._ It is an interesting fact that the skin of a sheep which comes from Persia is not the same kind of a skin as that of a sheep which is raised in the United States. In general, it may be said that skins from animals inhabiting warm countries are more likely to be serviceable than those from the same kind of animals inhabiting cold countries. In the cold countries more of the strength goes into the fur or hair which protects it, while in warm countries a greater amount of strength goes into the skin itself.
In addition to variations due to these causes there is likely to be a certain amount of variation in different parts of the same skin. That part of the skin which comes from the back of the animal is tougher than that which comes from the abdomen. The difference is very noticeable in the skins of some animals, less so in others.
_Decay of Leather._ Of late years there has been much dissatisfaction expressed over the decay of modern leathers. In many cases leathers 100 years old or more are in a fair state of preservation, while many leathers--perhaps we should say most leathers--30, 20 or even 10 years old, show signs of decay, and some have rotted away almost entirely. In no way is the decay of modern leathers shown more conclusively than in a long file of the sheep-bound set of the United States Public Documents. The earlier volumes, covering the 15th Congress up to the 36th, will in general be found to be in a good state of preservation. About the year 1860, however, marked deterioration appears. In some cases it seems as if the backs had entirely disintegrated. While a sheep-bound set is the best example of the decay of modern leathers, many libraries have been greatly annoyed by the decay of other leathers which are supposed to be much stronger than sheepskin.
So great was the dissatisfaction with modern leathers that in the year 1900 the Society of Arts in London appointed a committee to investigate modern leathers and to ascertain the best methods for preparing leathers for binding. The report of this committee was published in 1905, and a general knowledge of its contents is necessary for those who wish to know why leathers decay and how they may be preserved. Another valuable work which should be carefully studied is entitled "Leathers for libraries," published by the Sound Leather Committee of the Library Association in England. In a chapter of this book J. Gordon Parker, Ph. D., Director of the London Leather Industries Research Laboratories, tells us that the chief causes of decay are as follows:
1. The introduction of tanning materials other than oak and sumac, stronger in tannin, and more rapid in their action. Many of these tanning materials are unstable, and the leather produced disintegrates on exposure to light and air.
Tanning is the process of changing hides, which are animal matter subject to decay, into material which is strong and flexible and which is not subject to decay. There are two groups of tanning materials. The one called the pyrogallol group, which includes sumac, gall nuts and oak bark, is commended by the Committee of the Society of Arts. The other is called the catechol group and is strongly condemned. Among the materials belonging to the catechol group are hemlock bark and larch, used chiefly in this country, and turwar bark used largely in tanning East Indian goat and sheep skins.
The United States Government Printing Office proposals call for leathers tanned with a pyrogallol tannin, since it has been proved that such leathers prove most resistant to the evil effects of light, heat and gas. If a skin has been tanned with sumac, or sumac in combination with oak bark, it has received the best possible preparation for its life as a bookbinding leather.
It is not possible, neither is it necessary, to have all leathers tanned with sumac. Those leathers which are intended to remain on the shelves for many decades, should be in this tannage. Those which will be discarded in a few years may be tanned in a less expensive manner. Even some of the quick, modern materials, which accomplish in a few hours what once would have taken weeks, are not too poor for leathers which are not to be kept indefinitely.
Even the expert cannot detect skins which have not been tanned and dyed properly, but leathers which last a short time may be suspected either of being improperly tanned or of having some kind of injurious acid in their composition.
2. The use of dried and cured skins of variable soundness imported from abroad. Goat, calf and sheep skins are imported into this country (England) from all over the world; some are simply dried in the sun, some salted, whilst others are cured with various ingredients.
3. The use of infusions of acids and other bleaching agents to produce bright and even shades of colour.
Skins tanned with sumac are light-colored and can be dyed any desired color. Most other tanning materials, however, make darker-colored skins, which can be dyed only with dark colors. It has been found possible to scour and bleach skins with sulphuric acid and to re-tan with sumac.
4. The use of sulphuric or other mineral acids for the purpose of developing the depth of colour during the process of dyeing.
Sulphuric acid is the cause of decay of over 90% of modern bookbinding leathers. Having once been used, it cannot be wholly removed without the use of other chemicals.
5. The shaving and splitting of skins for producing an even substance.
In splitting and shaving, the long, strongest fibres of the skin are torn or cut off, and the part which remains for binding purposes is the weakest part of the skin.
6. Printing and embossing grains upon leather, together with other methods of finishing now in common use.
There are various ways of bringing out the natural grain of leathers which are perfectly legitimate and which do no harm. The danger in graining comes when the grain is embossed by means of a plate, which is heated and pressed on the skin. No good leather should ever be embossed.
7. The stripping, scouring, souring and re-tanning of East India leathers (Persians).
Some imported skins are only partially tanned, and it is necessary to wash out the tannin with some kind of alkali, which also takes out much of the natural grease of the skin. They are then treated with sulphuric acid and re-tanned. They are always poor and are seldom sold as re-tanned skins.
8. The removal of the natural grease or nourishment of the skin.
The foregoing eight causes of decay are beyond our direct control. The leathers are manufactured and put on the market, and the binder has to use such as he is able to obtain. No matter how much the librarian may insist upon leathers free-from-acid, he is helpless if the binder cannot obtain them. All that he can do is to insist that leathers without acid must be used, if obtainable.
Although these causes of decay are beyond the librarian's control, there are several causes of decay quite within his power to avoid. They are the following, due to improper methods used in binding, or to physical conditions after the book is on the shelf:
1. Direct sunlight.
2. Gas fumes. This evil is hard to guard against if there are gas pipes in the building. There is sure to be more or less leakage, and even a small amount of gas in the air has a bad effect upon leather.
3. Tobacco smoke. This is not likely to be very detrimental in libraries, since the rules generally forbid smoking.
4. Excessive dampness, which encourages mildew.
5. Extreme dry heat. A temperature much in excess of 70° Fahrenheit is likely to dry up the oil which gives flexibility to leather.
6. Undue wetting or stretching the leather in covering. Some binders soak the leathers and stretch them in placing them on the books. When the leathers dry they shrink, the fibres are strained and the life of the leather shortened.
7. Use of poor paste in binding. This frequently sets up a fermentation that is very harmful to leathers.
8. Dust, especially in conjunction with dampness, is very injurious to leather.
Doubtless there are other things which have a deleterious effect upon leathers in libraries; but if a library is well ventilated, if leather-covered books are not kept in cellars or basements that are very damp, or where direct sunlight can fall upon them, and if the binder uses good paste and proper care in covering the books, we may reasonably place the responsibility of undue decay of leathers upon the manufacturers.
The various reports quoted so far have dealt with qualities of leathers due to tanning, manufacture, method of binding and time in use. Natural or mechanical qualities of leathers have not been touched upon. Those who are interested in this phase of the question should read the report of Mr. Cedric Chivers on "The relative value of leathers and other binding materials," made at the meeting of the American Library Association at Pasadena in 1911. Mr. Chivers employed Mr. Alfred Seymour Jones, in England, to make tests which would show the tearing and breaking strain of various leathers. These natural qualities of leathers are obviously important, but too much stress must not be laid upon them. It is possible that a leather naturally strong and tough when new would rapidly deteriorate with age. The records as presented in Mr. Chivers' report must be taken in conjunction with facts determined by the investigation of the Society of Arts. In the main, however, it will be found that leathers which best stood the tests of the Society of Arts also showed the greatest resistance to the tearing and breaking strains made by Mr. Chivers.
_Preservation of Leather._ Various attempts have been made both by librarians and others to discover some substance which would preserve leather effectually after the book is bound. Some of these attempts have been temporarily successful, but time alone will tell whether leathers are permanently preserved by the treatments used, or whether applications of the preservative must be frequently made. Owing to the fact that in law libraries practically all the books published previous to 1900 were bound in sheepskin, the lasting qualities of leathers is a question that affects law libraries more than any other. Dr. Wire, of the Worcester (Mass.) County Law Library, who has made a careful study of the problem, advises the use of vaseline or some other similar by-product of petroleum well rubbed into the leather with the bare hand and allowed to dry in the air until the leather has absorbed it. Better results were obtained by allowing the volumes to dry in the summer by natural heat instead of artificial heat in the winter. For some books Dr. Wire makes use of a bookbinder's varnish after the softening product has thoroughly penetrated the leather. A full description of the processes may be obtained from Dr. Wire's pamphlet, "Leather preservation," published in 1911.
Some of the disadvantages of Dr. Wire's method are:
1. The necessity of rubbing in the preservative from three to five times, according to the condition of the leather at the time of first treatment.
2. The care necessary to prevent the material used from smearing tables, trucks, floor, shelves and clothing at time of application; also when books are back on the shelves the care required to keep from rubbing against them and the necessity of wiping them off when they are handed to readers.
3. The tendency of books to swell at the back when first treated in this way, demanding extra care lest, in an effort to pull out one book, a whole shelf-full fall to the floor.
4. The repetition of the process after ten years.
It is possible that these drawbacks will be sufficient to dissuade all except the most stout-hearted from using this method of preserving leather. Rebinding in cloth seems to be much more simple and, on the whole, not much more expensive.
The question of a preservative is discussed in the Report of the Society of Arts, from which the following quotation is taken:
Enquiries have frequently been made as to the use of preservative pastes upon old bindings. It has been mentioned that the seasonings of white of egg or blood albumen usually employed in finishing leather have some preservative effect, and no harm can arise from the application of very thin coatings of white of egg. The use of ammonia to thin or preserve the solution must be avoided, but the whites, after thorough beating, may be rendered antiseptic by the addition of a small quantity of camphor, thymol, or some essential oil. Vaseline has been employed as a dressing, and, if otherwise suitable, will no doubt have a preservative effect upon the leather. A very moderate use of the wax, soap, and turpentine preparations made as shoe pastes, is also likely to be beneficial, and no doubt a special preparation might be made on these lines which would be still more suitable. Paraffin wax dissolved in benzine is also harmless, and the surface to which it has been applied takes a good polish with a flannel after drying. Professor Proctor has experimented with a finish introduced by the Berlin Aniline Company some years ago for coloured leathers, with apparently satisfactory results. The preparation is practically a very hard stearine soap with excess of stearic acid, and is made by boiling 8 parts of stearic acid with 1 part of caustic soda and 50 parts of water until thoroughly dissolved, and then adding 150 parts of cold water and stirring till the material sets to a jelly. It is applied very thinly with a sponge or rag, and after thorough drying is polished with a soft brush or flannel. The alkali present in the soap is useful in neutralising any mineral acids contained in the leather. In very acid leathers it has been noticed that the sodium sulphate so formed will sometimes appear upon the surface as a white film, but this is easily removed with a damp cloth, and the surface, after drying, repolished with flannel.
Old books which it is desirable to preserve as long as possible in their original bindings and books which will be used very little may be treated with some form of preservative. If the book is to be much used, it would better be rebound. Dr. Wire's experiments have been carried on exclusively with law books. Whether the same processes could be used on books bound in morocco or pigskin is something that has not yet been determined. Most leather-bound books break first at the joint. The sheep bindings in a law library would show signs of disintegration long before the leather reached the breaking point, whereas the librarian would first notice that morocco was decaying when the leather actually cracked. Once cracked, no amount of preservative would do any good.
KINDS OF LEATHER[3]
The leathers that have been used in binding books have come from all sorts of animals, but so far as the librarian is concerned the skins of four animals only need be taken into consideration--the sheep, the cow, the pig and the goat. In England some experiments have been made with sealskin, but it has not been used long enough to give any definite idea of its resistance to the encroachments of time.
Footnote 3: The prices of leathers given in the text are those which prevailed during the summer of 1915.
SHEEPSKIN
Sheepskin is a soft, flexible leather with weak fibres, and with a surface easily abraded. It has been used for bindings practically ever since books were put into leathers; and, under the old methods of tanning and manufacturing, proved satisfactory. In many libraries it is possible to see leather books bound in sheep in the 17th century which are in a good state of preservation. Even the sheep of the beginning of the 19th century is frequently well preserved. Since 1860, however, the quality of sheep has greatly deteriorated. This is bad enough, but unfortunately sheep likes to masquerade under the name of morocco and other leathers of a better grade, so that its use is much more extensive than appears at first sight. In the process of imitation the grain of the leather imitated is stamped on the skin. When this is done it generally takes an expert to detect the fact that the leather is not what it pretends to be, and even experts are sometimes deceived after the leather is on a book.
The strongest sheepskins are made when tanned with oak bark. Sumac, which is such a valuable tanning material with other leathers, is here inferior to oak.
There are two kinds of sheepskin, the wool sheep which is known to all, and the hair sheep which is not found in the United States, and which in reality is a cross between a sheep and a goat. The hair sheep comes from India, China, South America and Africa, generally from mountainous districts. It has a much tougher fibre and is a better wearing skin than that of the wool sheep. Unfortunately most of these skins, which are all imported, are made into shoe leather. When properly tanned they are very suitable for library binding, and their use for that purpose is increasing.
The wool sheepskin in its natural color has been used for many years for binding law books. It is seldom used for anything except government documents and law books, and for this reason is known as "law-sheep."
_Roan._ Roans, the term used for sheepskins after they are dyed, can be used advantageously on books which will be handled a great deal, and which in any event will not stay on the shelves indefinitely. Properly tanned and dyed, they make a satisfactory leather for a time, but their life under the best of conditions seldom exceeds ten or twelve years. While this is true of good roans, it unfortunately remains true that in the United States, at least, it is difficult to get roans that are properly tanned and dyed. Therefore, unless one is sure that the quality of the skin is the best, he should use no sheep under any conditions.
_Skiver._ Skiver is the outside of a sheepskin which has been split, the inner side being known as the flesher. It is a leather much used for commercial binding, but since the splitting process takes away a great part of the strength of the skin, leaving it not much stronger than strong paper, skiver is wholly unfitted for library use.
COWHIDE
Cowhide, sometimes known as American russia, is a leather which has increased enormously in use in the last twenty-five years. It is a thick, coarse leather, rather unattractive in appearance, strong when new, but with age rapidly deteriorating in quality, even when no deleterious substance has been used in tanning or dyeing. It is a harder leather to work than roan, but the quality is much more uniform and it can be used advantageously for binding fiction and other books which will be much used. In its natural state (undyed) it can be used in place of law-sheep for law books, but has a tendency to become dark. It can be obtained in many colors. Since it is too thick a leather to be used in full thickness, practically all skins are split, and the amount of flesh left with the grain determines the weight of the leather. A greater or less amount is taken off according to the purpose for which the leather is intended. Bookbinding cowhide costing 20c to 25c. a square foot is the lightest weight leather that has the right to be called cow.[4] The life of cowhide is from five to twelve years.
_Buffing._ Buffing is practically only the grain of cowskin from which almost all the flesh has been split. It is not suitable for library books, since it is very thin and begins to disintegrate in less than five years. After it is on the volume it is hard to detect, so that some library binders have been tempted to use it instead of cow. But as buffing is never sold as cow, the library binder has no excuse for keeping it in stock.
Footnote 4: This is the normal price of cow. The European war has had the disastrous effect of raising the price and lowering the quality. Until conditions become normal again all cowhide should be shunned.
PIGSKIN
Pigskin is one of the strongest leathers, having a hard, resisting surface and a good, tough fibre. In the grain, the holes which were left when bristles were removed are plainly visible, giving the leather a distinctive appearance, which can be imitated successfully, but which is much less often imitated than the grain of morocco. If there be doubt of the genuineness of pig, soak a piece of the leather until it has absorbed a quantity of water, and then stretch it. If the grain pulls out, it is imitation; if genuine, the bristle holes still show plainly. Oak bark tanning is the best for this leather, and, since it is more nearly gristle (less fibrous) than other leathers, dyes and chemicals should not be used which will interfere with its quality of resisting friction. It should be used in its natural color whenever possible.
Pigskin frequently comes in skins which are too thick for the binder to work easily, or which are very uneven in thickness. In such cases the paring down of the skin is likely to injure its strength. Because of its thickness pig is generally supposed to be more suitable for large than for small books, but inasmuch as several binders have used it successfully for years on small books, it may be taken for granted that it can be used with good results on all books, large or small, which are to receive hard usage. It needs constant handling, and the absorption of a certain amount of oil from the hands to keep it pliable. Otherwise it dries rapidly and cracks along the joint. This, however, is true of all leathers to a greater or less extent. Pig costs from 40c. to 45c. a square foot.
GOAT
The leather which makes the strongest and most attractive binding comes from the skins of goats and is called morocco, because it originally came from that country. In the course of time goat skins from other countries were tanned with sumac (originally a distinguishing characteristic of a genuine morocco), but the same name was applied so that we now have the paradoxical terms, Turkey morocco, Levant morocco, etc. Moroccos have a beautiful grain, are flexible, soft and pliable to the hand, and resist hard wear; qualities which contribute to their great popularity.
Morocco varies greatly in quality as well as in appearance. Unfortunately the skins which are best in quality, considering the length of time they will wear, are not always those best in appearance. The skins of goats with long hair from the colder countries make beautiful bindings; but the skins of goats from the hot countries, such as the interior of Africa, having short hair, while not so attractive in appearance, are tougher and wear longer. In addition to the many grades of genuine morocco there are as many more imitations of it made from sheepskin, cowhide, etc. Only the expert can detect some of them in the skin, and even he may be deceived when the leather is on the back of the book.
In general it should be said that genuine morocco is the most expensive leather that a library can use, and that it can be used to the greatest advantage only occasionally. It makes an excellent binding for large reference books which are constantly handled, for art books which must be attractively bound, and for some periodicals which are much used in reference work. It is not used nearly so much in libraries to-day as it was ten or fifteen years ago, and it is quite safe to say that it will be used less ten years from to-day than it is now.
_Levant morocco_, made from the skins of Angora goats, is the most expensive and most beautiful leather used in binding. It has a large, prominent grain, but is far too expensive for any library to use, especially when it must be conceded that in its wearing quality it does not equal that of some less expensive moroccos. Mr. Chivers' test showed that so far as tensile strength goes, this leather is very much weaker than many leathers much less expensive. When the skin has been subjected to pressure until the surface is smooth it is known as "crushed levant."
_Turkey morocco_, made of skins of goats from Turkey, is a very strong, durable leather which all libraries will find occasion to use from time to time. It is very easily imitated. Under exposure to atmospheric conditions existing in many libraries its life may not extend beyond thirty years. In one library at least, where conditions of light and heat were poor, the best Turkey morocco that the market afforded showed signs of disintegration within twelve years. Good Turkey morocco can be obtained for 35c. a square foot.
_Persian morocco_, which comes from the skin of a Persian sheep (not goat), is not particularly attractive in appearance and is very poor in quality. It is used extensively for commercial work, but is absolutely valueless for library binding.
_Niger morocco_ is a goat skin which comes from the interior of Africa, generally by way of Tripoli, and is by no means a recent discovery, though we knew little about it five years ago. It is tanned by natives according to some method of vegetable tanning not completely known at this time. While in appearance it is not so attractive as some other moroccos, because of blemishes due to carelessness in handling and to the imperfect removal of some of the hairs, it has been proved by the tests made under the direction of Mr. Chivers to be stronger than all other moroccos; the inference is that it is more durable. Until recently it has been very hard to obtain in the United States.
_Bock morocco_ is not a morocco but a split Persian sheep so poor in quality that it is mentioned only to be condemned.
CALFSKIN
Calfskin in all its various characters, such as divinity, kip, marbled, mottled, smooth, tree, or just plain calf is a very beautiful leather much used in the past for binding books for individuals. For this purpose it has, of late years, been crowded out by Levant morocco. It has a soft, smooth surface which disintegrates rapidly under the action of heat and gas and has little strength even for temporary use. For the library it is useless.
RUSSIA LEATHER
This is a brownish-red leather made from the skins of different animals, tanned with willow bark and filled with a preparation of birch oil which gives it its peculiar odor. Neither in its genuine form nor in imitation is it a useful leather for libraries.
SEALSKIN
Although experiments have been made with it in some English libraries sealskin has never been much used in the United States for library binding. It is made from the skins of the hair seal, the supply coming from all parts of the North Atlantic Ocean. According to Mr. Douglas Cockerell and other binding experts in England, the skin is peculiarly suited for library use. It is reported to be a hard-wearing leather, tough and pliable, even in quality so that no part of the skin must be discarded because too thin or too weak, and possessing a beautiful grain. The price ranges from a point somewhat higher than that of the poorer moroccos to one somewhat lower than the higher prices. Unfortunately it can be easily imitated.
VELLUM
Probably no discussion of leather is complete without mentioning vellum, a binding material which does not resemble leather, but which nevertheless is made from calfskin or sometimes from goat skin. It is prepared by the use of lime, and as far as the actual wear on flat surface is concerned, is perhaps better than any leather. It is, however, very susceptible to moisture, which makes it warp; and to light, which makes it hard and brittle. Since it is very hard, does not bend easily and is hard to work, its chief use is on the corners of books to protect them and make them less likely to break or rub. Large libraries have used it somewhat for this purpose, but the use is dying out.
In making a study of leathers it is well to obtain samples of all kinds, including those which are unsuitable for library use, and to examine them carefully, noting the appearance of the grain, thickness of skin, flexibility, and softness of surface. Perhaps more money can be wasted through ignorance of the comparative values of different kinds of leather which it is permissible to use in library binding, than in mismanagement of any other part of binding.
CLOTH
Cloth is fully as important as leather in the economy of binding. Several years ago it was the custom to bind periodicals and other books which were used comparatively seldom in leather, while fiction, juvenile and other books which wore out quickly were bound in cloth. Recently the opposite course has been more favored. Books which receive unusually hard usage and are in the hands of readers constantly are bound in leather; while those which are used seldom, including periodicals, are bound in some kind of cloth. Without doubt the change is a wise one. Even the best of leather disintegrates in time under the action of heat, gas, light, etc., and to-day many a volume bound in leather ten or fifteen years ago has parted from its sides, necessitating rebinding or recovering. Had it been bound in a good quality of cloth it would to-day be in good condition, and probably would remain in good condition for a hundred years. It requires considerable courage to change the binding of a good set of a standard periodical, such as the Atlantic or Harper's, from an attractive half morocco binding to an unattractive buckram. Unquestionably, if economy is an object, the change should be made, except possibly in the case of a library which uses these periodicals daily. Every librarian must decide each case for himself strictly according to the use the set is to receive, always bearing in mind the fact that leather disintegrates with time, whereas cloth does not unless exposed to excessive moisture.
No cloth which is suitable for library use is perfectly satisfactory because it has not the strength of good leather, cannot be used advantageously on very heavy books, soils easily and with use grows soft and flabby, especially along the joints. But on the other hand even those not suitable for libraries which are used by the publisher on cheap books are much better than poor grades of leathers, such as skiver, bock, buffing, etc.
The requisite qualities of a good cloth are:
(_a_) Endurance when folded back and forth in the same place, so that it may withstand the wear at the joint caused by opening the book.
(_b_) Smoothness, so that there will be a comparatively small amount of friction when withdrawing a book from between two others on the shelf.
(_c_) Ability to withstand constant rubbing back and forth on tables.
(_d_) Color that is fast when exposed to light; if possible it should be fast to water also, though this is less important.
(_e_) Color should be dyed in the piece, not pressed in by machinery.
Many cloths have some of these qualities but few have all of them. So far as is known to the writer only the grade of cloth described on page 77 has the last qualification.
Practically all cloth used in the United States is made of cotton. The best cloths are manufactured by The Holliston Mills, Norwood, Mass.; The Interlaken Mills, New York City; The Joseph Bancroft & Sons Company, Wilmington, Del., and by the Winterbottom Company and the Manchester Book Cloth Company in England. Since a number of grades are made in several different patterns and a great number of shades for each grade and each pattern, a variety of choice is permitted. As a matter of fact, however, most librarians select a good grade with a regular weave and confine themselves to a few standard shades, such as dark green, brown, red, dark blue, and tan.
Since the strength of the warp is much greater than that of the weft, it is advisable when possible to cover books with the warp running across the cover. This, however, may entail some hardship on the binder for it may frequently happen that in order to cut his cover economically he must make the warp run lengthwise of the book. If a strong cloth is used the advantage is not great enough to be insisted upon.
Each of the American firms mentioned makes three distinct grades, all of which libraries may use. Each firm uses a different name for each grade. In other words, there are no general names which can be used for the corresponding grade in all makes. Therefore for the purposes of this chapter these cloths will be considered under the heads of Grades 1, 2 and 3, but it must be remembered that this is an arbitrary designation not known to the trade. Under each grade will be given the specific names used by the three manufacturers.
GRADE 1
Grade one of cloth, the cheapest that a librarian may use, is not made of the best quality of cotton thread and should never be used under any circumstances for full binding. It may be used on the sides of books bound in leather; if this be done the corners should be covered with vellum, for this cloth does not withstand hard usage and is likely to fray at the corners. It is a cloth commonly used by publishers, but should be used sparingly by the librarian. "Art vellum" made by the Interlaken Mills, "Aldine vellum" made by the Holliston Mills, and "Linen finish" made by the Joseph Bancroft & Sons Company, come within this grade.
GRADE 2
(_a_) Grade two is made of a better grade of cotton and with a closer weave than the preceding, but is not sufficiently strong to be used for full binding. It can be used more satisfactorily than the preceding on the sides of books bound in leather or duck. In common with all cloths, except the buckram made according to the government specifications (which will be discussed later), the different colors are not made, as one might suppose, by dyeing the cloth after it is woven, but by mixing the color with the sizing or starch which is used in finishing the cloth, and pressing it into the cloth by machinery. As a natural result the color rubs off with wear and the natural gray of the original cloth as first woven appears. "Art canvas" made by the Interlaken Mills, "Classic buckram" made by the Holliston Mills, and "Polished buckram," by the Joseph Bancroft & Sons Company come within this grade.
(_b_) _Buckram._ Under the name of buckram various grades of cloth are manufactured which resemble to a greater or less degree those mentioned under Grade 2 (_a_). Generally it is a coarsely woven cloth stiffened with glue or sizing, and the term originally indicated that the cloth was made of linen. At the present time linen buckram made in England can be obtained, but all that is manufactured in the United States is made of cotton. Linen buckram costs much more than cotton and it is doubtful if it is any more serviceable. All of the three manufacturers mentioned make buckrams.
GRADE 3
Prior to 1907 the Congressional set of government documents distributed to the depository libraries had been bound in sheepskin and the leather on the volumes had disintegrated so much as to make the set a hard one to care for. In 1907 the Congressional Printing Investigation Commission asked librarians of depository libraries to suggest, without considering cost, suitable binding materials for Government Documents. The number of replies received was 124, embodying suggestions as follows: full sheep, 11; half-russia, 78; cloth, 25; buckram, 70; linen duck, 20; canvas, 19. Some librarians expressed more than one preference, so that the total number of preferences was greater than the total of those replying. Most of those who favored sheep did so because of their desire for uniformity. Those who favored half-russia undoubtedly desired half American russia, or cowhide. 134 expressed preference for some form of cloth.
After receiving the replies from librarians the Printing Investigation Commission obtained samples of cloth from various cloth manufacturers in the United States and the Bureau of Standards made a series of chemical and physical tests to determine the durability of these cloths. Chemical tests were made to discover whether the colors were fast when exposed to light. It is to be regretted perhaps that no tests were made to determine whether the cloths were fast to water and that this qualification was not included in the final specifications. Admitting, however, that a cloth which is fast to sun and water both is a valuable cloth for bookbinding, it is evident that the quality of fastness to water is not a vitally important one for cloth used in the United States. The total number of books injured by water is so small as to make insistence upon this quality entirely unnecessary. If books become so soiled that they need to be washed they should be bound in waterproof cloth.
Because many volumes of Government Documents are sent to Porto Rico and the Philippines where insects eat almost anything of an animal or vegetable character, the desirability of the cloth as an article of diet for insects, was also tested.
The physical tests indicated:
_a._ Number of threads per inch of warp and weft.
_b._ Absorption of moisture.
_c._ Weight per yard.
_d._ Tensile strength.
_e._ Amount of stretch.
_f._ Amount of friction developed by rubbing two pieces of cloth together.
This test was made because the friction developed in taking a book from between two others is an important matter when a shelf is full of books. If the friction is great the wear on the back of the book is correspondingly excessive.
_g._ Endurance when folded back and forth in the same place.
_h._ Endurance under extraordinary conditions of rubbing.
Some of these qualities, such as tensile strength, amount of stretch, etc., were comparatively unimportant, but the tests for all were severe and contributed much to our knowledge of the qualities which should enter into the composition of durable book cloths.
After a very careful consideration of the results of the tests and a thorough examination of the samples submitted, a committee of librarians and government officials unanimously chose three samples as the best of all those submitted by the manufacturers. Of these three samples the cloth numbered 666 was considered the most satisfactory.
Although these three samples were excellent, they all had one defect--the color was pressed in by machinery, not dyed in the piece. After various experiments had been made by the manufacturers this defect was remedied. The Government Printing Office then advertised for bids on cloths which would meet the Specifications drawn up by the Bureau of Standards (See Appendix A). Since that time all the Government documents which continue the old sheep-bound set have been sent to depository libraries bound in cloth made according to these specifications.
This cloth is known sometimes as Government Specification Cloth, but is manufactured under the specific name of "Library buckram" by the Holliston Mills, "Art buckram" by the Interlaken Mills, and "Legal buckram" by the Joseph Bancroft & Sons Company. The first two are made in pieces about 40 yards long and 38 inches wide, the Bancroft cloth in pieces 43 yards long and 43 inches wide. It must be admitted that this cloth is not quite so attractive in appearance as some of the old cloths which are not so durable. Some binders claim that it is hard to use. On the whole, however, it supplies a long felt want and is the strongest cloth made that is at all attractive in appearance.
DUCK
Duck or canvas, a rough, heavy cloth much the same in quality as sail cloth, is the strongest cloth used in binding, but has some very decided drawbacks which militate against its use, except when the question of strength overshadows all others. It always makes an unattractive-looking volume--some of the more fastidious librarians rebel against its use; and it readily absorbs dirt and moisture, making it disagreeable to handle if the book has been much used. Duck having a double twisted thread in the weft is much more compact and absorbs dirt and moisture much less rapidly than other kinds. It should be used on the backs (never for full binding) of newspapers and such periodicals as are too heavy to put in library or legal buckram.
IMPERIAL MOROCCO CLOTH
Imperial morocco cloth, manufactured by the Winterbottom Book Cloth Company in England, is made of linen thread and finished with a grain to resemble leather. The kind most used in the United States resembles a straight-grained morocco. It is an excellent cloth in appearance, as well as in durability, but its cost is 50% greater than that of the Government Specification Cloth. It may be used on semi-popular books which will not receive a great amount of use, but which should be as attractive in appearance as possible.
WATER-PROOF CLOTHS
There are several cloths which are waterproof and therefore easily cleaned when the covers become soiled. The best of these are durabline, used exclusively by Cedric Chivers; rexine and pluviusin, used almost exclusively in England; keratol, made in Newark, New Jersey; and fabrikoid, made by the du Pont Powder Company, Wilmington, Delaware. All of these cloths are said to be acid, alkali and germ proof, do not absorb grease and can be washed with soap and water. They are strong, durable cloths, but they have at first a disagreeable odor, are hard to work and hard to letter in gold. In the application of paste to most waterproof cloths, either in the process of binding or in attaching labels to the back, it is first necessary to break down the surface of the cloth or the paste will not hold. This disadvantage no longer exists in the case of fabrikoid. Keratol and fabrikoid are made to imitate leather and are frankly sold as such. Probably the use of these cloths in libraries will always be comparatively small. Because they can be easily cleaned they may be used on the sides of juvenile books, and in rare cases for full binding.
GLUE
No very definite rules can be laid down as to what kind of glue should be used. The matter must be left largely in the hands of the binder, who must see that it is strong, yet flexible; not too poor in quality nor yet the most expensive kind which is generally used on furniture. This is too brittle for bookbinding use.
The best glue for bookbinding is made from skins and shows a dark wine color in the cake. Light colored glues are made chiefly from bones and are not usually so good. To prepare glue for use, soak small pieces in water over night and in the morning melt in the glue pot. It should never be boiled. A careful binder will see that utensils are kept clean and that glue is used in the proper thickness.
Flexible glue, which does not become too hard either before or after use, is made by mixing glycerine with good glue. It has no special advantages for use by binders, but can be used in the library itself for some of the repairs which assistants may have to make.
PASTE
(For paste used in mending, see p. 167).
The best paste is that made in the ordinary way with flour and water. The paste should be fresh, for if it is not a certain fermentation takes place which is injurious to the book, especially to leather.
BOARDS
Not the least important part of the make-up of a finished book are the boards forming the sides. There are practically four grades of boards which are known as strawboards; binders, cloth or millboards; semi-tar, and tar boards. The cheapest grade is the strawboard, for which there is no place in library work.
Mill or cloth boards, used for practically all library work, are generally made from waste papers of all kinds, though some may have an admixture of rags. Clay is also mixed with the waste paper pulp and the whole subjected to heavy pressure in the final stages of manufacture. They are made in two sizes, 20 × 30 and 23 × 29 inches, and are put up in 50-pound bundles, the number of sheets in the bundle indicating the thickness of the board. The thickest is a No. 12 which has 12 sheets in a 50-pound bundle. They may have as many as 70 sheets in a bundle, which makes a very thin board. A 20 or 25 board should be used for fiction and juvenile books and a 16 or 18 for heavier books such as magazines. Prices of good cloth boards run from $40 to $50 a ton.
Semi-tar boards, made from better grade stock than mill board, should have in their composition a certain amount of rags and hemp or naval cordage. They come in the same sizes and weights, costing about $70 a ton.
Tar boards are the best boards obtainable. Made of naval cordage, they are very tough and hard to work. Many of them are allowed to season, in much the same way as lumber seasons, in order to prevent warping. They are much too expensive for library use, sometimes costing as much as $110 a ton.
The matter of boards is not one about which the librarian need exercise great watchfulness. Binders generally use a very good quality, though they sometimes use too thin a board on a heavy book, such as a newspaper or large folio. In such cases a board of suitable thickness can be made by pasting or gluing two or more together.
THREAD
At one time there was no question but that the best thread to be used in binding was linen. In the light of present knowledge it may be doubted if this is true under all circumstances. All commercially bound books, without exception, are sewed with cotton thread. Even such large books as the Century Dictionary, Webster's Dictionary and the United States Catalog of 1912 are sewed with cotton thread. Since it was unquestionably the aim of the publishers of all these books to issue them in the strongest possible bindings, it is reasonable to suppose that linen would have been used if it were really the best for the purpose. The main reason linen thread has been advised for so long is because its tensile strength is much greater than that of cotton. On the other hand, it is just as true that what we may call the fraying resistance of a cotton thread is greater than that of linen. Take two threads of the same size, one cotton and the other linen, make a loop of each thread with one inside the other, saw back and forth, and the cotton will always cut the linen thread. Furthermore, linen thread deteriorates in quality unless very carefully stored. The publishers soon discovered these facts, and since tensile strength is not an important attribute in a thread that is being used in a book sewing-machine, they use a cotton thread with thoroughly satisfactory results.
In the case of library binding, however, the books are always sewed by hand and the sewer, as she draws the thread tight, is obliged to use some strength; for this reason tensile strength is an important attribute. Hayes' Irish linen thread is generally specified. The Barbour thread is referred to by Mr. Dana and by others, but the writer is not familiar with its use.
Other materials used in binding are gold leaf, paper for end papers, tape, headbands, cord and various concoctions used in finishing the books. Gold leaf should be 18 to 22 karat, and neither aluminum nor silver leaf should be used. Paper for end papers will vary somewhat with the size of the book, but should never be lighter in weight than a 60-pound manila. Large libraries may find it desirable to have an end paper specially made for their own use. Tapes should be linen and not over three-eighths of an inch wide. Cord for use in sewing in the regular way (not overcasting) is a soft twine which can be obtained from all dealers in bookbinding supplies. For all books less than twelve inches in height use four-ply cord; for larger books, five-ply.