[Ill.u.s.tration: FIG. 28.]
To fasten the cord below, a key is taken (see fig. 28) and held below the press by the right hand; the cord is then pulled up round it by the left, and held in position on the key by the first finger of the right hand. The key is then turned over, winding up a little of the string, and the p.r.o.ngs slipped over the main cord. It is then put through the slit in the bed of the sewing-press, with the p.r.o.ngs away from the front. The cord is then cut off, and the same operation repeated for each band. When all the bands have been set up, the book is laid against them, and they are moved to correspond with the marks previously made on the back of the book, care being taken that they are quite perpendicular. If they are of the same length and evenly set up, on s.c.r.e.w.i.n.g up the crossbar they should all tighten equally.
It will be found to be convenient to set up the cords as far to the right hand of the press as possible, as then there will be room for the sewer"s left arm on the inner side of the left hand upright.
A roll of paper that will exactly fill the slot in the sewing-frame is pushed in in front of the upright cords to steady them and ensure that they are all in the same plane.
When the sewing-frame is ready, with the cords set up and adjusted, the book must be collated to make sure that neither sheets nor plates have been lost or misplaced during the previous operations. Plates need special care to see that the guards go properly round the sheets next them.
[Ill.u.s.tration: FIG. 29.]
The top back corner, on front and back waste end paper, should be marked. When this has been done, and all is found to be in order, the book is laid on a pressing-board behind the sewing-frame, the fore-edge towards the sewer, and the front end paper uppermost. As it is difficult to insert the needle into a section placed on the bed of the sewing-frame, it will be found convenient to sew upon a largish pressing-board, which will lie on the bed of the frame, and may have small catches to prevent it from shifting. When the board is in place, the first section (end paper) is taken in the left hand and turned over, so that the marks on the back come in the proper places against the strings. The left hand is inserted into the place where the sewing is to be, and with the right hand a needle and thread is pa.s.sed through the kettle st.i.tch mark (see fig. 29). It is grasped by the fingers of the left hand, is pa.s.sed out through the back at the first mark on the left-hand side of the first upright cord, and pulled tight, leaving a loose end of thread at the kettle st.i.tch. Then with the right hand it is inserted again in the same place, but from the other side of the cord, and so on round all five bands, and out again at the kettle st.i.tch mark at the tail, using right and left hands alternately. The centre of the next section is then found, and it is sewn in the same way from tail to head, the thread being tied to the loose end hanging from the first kettle st.i.tch. Another section is laid on and sewn, but when the kettle st.i.tch is reached, the under thread is caught up in the way shown in fig. 30. These operations are repeated throughout the whole book. If the back seems likely to swell too much, the sections can be lightly tapped down with a loaded stick made for the purpose, care being taken not to drive the sections inwards, as it is difficult to get such sections out again. When all the sheets and the last end paper have been sewn on, a double catch st.i.tch is made, and the end cut off. This method is known as flexible sewing "all along."
[Ill.u.s.tration: FIG. 30.]
[Ill.u.s.tration: FIG. 31.]
When one needle full of thread is exhausted, another is tied on, making practically a continuous length of thread going all along each section and round every band. The weaver"s knot is the best for joining the lengths of thread. A simple way of tying it is shown at fig. 31. A simple slip knot is made in the end of the new thread and put over the end of the old, and, on being pulled tight, the old thread should slip through, as shewn at B. The convenience of this knot is, that by its use a firm attachment can be made quite close up to the back of the book. This is a great advantage, as if the knot is made at some distance from the back, it will have to be dragged through the section two or three times, instead of only once. The knot, after having been made, must be pulled inside the section, and remain there. Considerable judgment is required in sewing. If a book is sewn too loosely, it is almost impossible to bind it firmly; and if too tightly, especially if the kettle st.i.tches have been drawn too tight, the thread may break in "backing," and the book have to be resewn.
One way to avoid having too much swelling in the back of a book consisting of a great many very thin sections is to sew "two sheets on." In this form of sewing two sections at a time are laid on the sewing-frame. The thread is inserted at the "kettle st.i.tch" of the lower section, and brought out as usual at the first cord, but instead of being reinserted into the lower section, it is pa.s.sed into the upper one, and so on, alternately pa.s.sing into the upper and lower sections. This will give, if there are five bands, three st.i.tches in each section instead of six, as there would be if the sewing were "all along," lessening the thread, consequently the swelling by half.
It is usual to sew the first and last few sections "all along."
The common method of sewing is to make saw cuts in the back, in which thin cords can be sunk, and the thread merely pa.s.ses behind them and not round them, as in flexible sewing. This method, although very quick and cheap, is not to be recommended, on account of the injury done to the backs of the sections by the saw, and because the glue running into the saw cuts is apt to make the back stiff, and to prevent the book from opening right to the back. Indeed, were a sawn-in book to open right to the back, as it is expected a flexibly-sewn book will do, showing the sewing along the centre of each section, the saw marks with the band inserted would show, and be a serious disfigurement.
Mediaeval books were usually sewn on double cords or strips of leather, and the headband was often sewn at the same time, as shown at fig. 32, A. This is an excellent method for very large books with heavy sections, and is specially suitable for large vellum ma.n.u.scripts, in many of which the sections are very thick. An advantage of this method is, that the twist round the double cord virtually makes a knot at every band, and should a thread at any place break, there is no danger of the rest of the thread coming loose. This is the only mode of sewing by which a thread runs absolutely from end to end of the sections. The headband sewn at the same time, and so tied down in every section, is firmer and stronger than if worked on in the way now usual. In the fifteenth century it was the custom to lace the ends of the headbands into the boards in the same way as the other bands. This method, while giving additional strength at the head and tail, and avoiding the somewhat unfinished look of the cut-off ends of the modern headband, is, on the whole, of doubtful advantage, as it is necessary to cut the "turn in" at the point where strength in the leather is much wanted.
At fig. 32 is shown in section the three methods of sewing mentioned.
A is the old sewing round double bands; with the headbands worked at the same time with the same thread; B is the modern flexible sewing, and C the common sawn-in method.
[Ill.u.s.tration: FIG. 32.]
Books that are very thin or are to be bound in vellum, are best sewn on tapes or vellum slips. The easiest way to set up the sewing-frame for such sewing is to sling a piece of wood through two of the lay cords, and to pin one end of the vellum or tape band round this, pull the other end tight, and secure it with a drawing-pin underneath the frame. The sewing, in the case of such flat bands, would not go round, but only across them. To avoid undue looseness, every three or four threads may be caught up at the back of the band, as shown in fig. 33.
[Ill.u.s.tration: FIG. 33.]
MATERIALS FOR SEWING
The cord used should be of the best hemp, specially made with only two strands of very long fibres to facilitate fraying out. For very large books where a double cord is to be used, the best water line will be found to answer, care being taken to select that which can be frayed out. If tape is used it should be unbleached, such as the sailmakers use. Thread should also be unbleached, as the unnecessary bleaching of most bookbinder"s sewing-thread seems to cause it to rot in a comparatively short time. Silk of the best quality is better than any thread. The ligature silk, undyed, as used by surgeons, is perhaps the strongest material, and can be had in various thicknesses. It is impossible to pay too great attention to the selection of sewing materials, as the permanency of the binding depends on their durability. The rebinding of valuable books is at best a necessary evil, and anything that makes frequent rebinding necessary, is not only objectionable on account of the cost involved, but because it seriously shortens the life of the book.
Experience is required to judge what thickness of thread to use for any given book. If the sections are very thin, a thin thread must be used, or the "swelling" of the back caused by the additional thickness of the thread in that part will be excessive, and make the book unmanageable in "backing." On the other hand, if the sections are large, and a too thin thread is used, there will not be enough swelling to make a firm "joint." Broadly speaking, when there are a great many very thin sections, the thinnest thread may be used; and coa.r.s.er thread may be used when the sections are thicker, or fewer in number. In the case of large ma.n.u.scripts on vellum it is best to use very thick silk, or even catgut. Vellum is so tough and durable, that any binding of a vellum book should be made as if it were expected to last for hundreds of years.
In selecting the thickness of cord for a book, some judgment is required. On an old book the bands are best made rather prominent by the use of thick cord, but the exact thickness to be used is a matter for taste and experience to decide.
A very thick band on a small book is clumsy, while a very thin band on the back of a heavy book suggests weakness, and is therefore unsightly.
In bindings of early printed books and ma.n.u.scripts an appearance of great strength is better than extreme neatness.
When the sewing is completed, the cords are cut off close to the lay cords, and then the keys will be loose enough to be easily removed.
The knots remaining on the lay bands are removed, and the keys slung through one of them.
CHAPTER VIII
Fraying out Slips--Glueing up--Rounding and Backing
FRAYING OUT SLIPS AND GLUEING UP
After sewing, the book should be looked through to see that all sheets and plates have been caught by the thread, and special attention should be given to end papers to see that the sewing lies evenly.
The ends of the cords should next be cut off to within about two inches of the book on each side, and the free portions frayed out. If proper sewing cord is used, this will be found to be very easily done, if a binder"s bodkin is first inserted between the two strands, separating them, and then again in the centre of each separated strand to still further straighten the fibres (see fig. 34).
The fraying out of the thick cord recommended for heavy books is a more difficult operation, but with a little trouble the fibres of any good cord can be frayed out. Vellum or tape bands will only require cutting off, leaving about two inches free on each side. The free parts of the bands are called slips.
[Ill.u.s.tration: FIG. 34.]
The book is now ready for glueing up. A piece of waste mill-board or an old cloth cover is put on each side over the slips, and the book knocked up squarely at the back and head. Then it is lowered into the lying press and screwed up, leaving the back with the protecting boards projecting about three-quarters of an inch. If the back has too much swelling in it or is spongy, it is better to leave the slips on one side free and to pull them as tight as possible while the book is held in the press, or a knocking-down iron may be placed on one side of the projecting back and the other side tapped with the backing hammer to make the sections lie close to one another, and then the slips pulled straight (fig. 35). The back must now be glued. The glue for this operation must be hot, and not too thick. It is very important that it should be worked well between the sections with the brush, and it is well after it has been applied to rub the back with a finger or folder to make quite sure that the glue goes between every section for its entire length. If the book is too tightly screwed up in the press, the glue is apt to remain too much on the surface; and if not tightly enough, it may penetrate too deeply between the sections. If the glue is thick, or stringy, it may be diluted with hot water and the glue-brush rapidly spun round in the glue-pot to break it up and to make it work freely.
[Ill.u.s.tration: FIG. 35.]
Very great care is needed to see that the head of a previously trimmed book is knocked up exactly square before the back is glued, for if it is not, it will be very difficult to get it even afterwards.
ROUNDING AND BACKING
The amount of rounding on the back of a book should be determined by the necessities of the case; that is to say, a back that has, through guarding, or excess of sewing, a tendency to be round, is best not forced to be flat, and a back that would naturally be flat, is best not forced to be unduly round. A very round back is objectionable where it can be avoided, because it takes up so much of the back margins of the sheets, and is apt to make the book stiff in opening.
On the other hand, a back that is quite flat has to be lined up stiffly, or it may become concave with use.
[Ill.u.s.tration: FIG. 36.]
The method of rounding is to place the book with the back projecting a little over the edge of the press or table, then to draw the back over towards the workman, and, while in this position, to tap it carefully with a hammer (see fig. 36). This is repeated on the other side of the book, and, if properly done, will give the back an even, convex form that should be in section, a portion of a circle. Rounding and backing are best done after the glue has ceased to be tacky, but before it has set hard.
[Ill.u.s.tration: FIG. 37.]
Backing is perhaps the most difficult and important operation in forwarding. The sewing threads in the back cause that part to be thicker than the rest of the book. Thus in a book with twenty sections there will be in the back, in addition to the thickness of the paper, twenty thicknesses of thread.
If the boards were laced on to the book without rounding or backing, and the book were pressed, the additional thickness of the back, having to go somewhere, would cause it to go either convex or concave, or else perhaps to crease up (see fig. 37). The object of rounding is to control the distribution of this swelling, and to make the back take an even and permanently convex form.
[Ill.u.s.tration: FIG. 38.]
If the boards were merely laced on after rounding, there would be a gap between the square ends of the board and the edge of the back (see fig. 38), though the convexity and even curve of the back would be to some extent a.s.sured. What is done in backing is to make a groove, into which the edges of the board will fit neatly, and to hammer the backs of the sections over one another from the centre outwards on both sides to form the "groove," to ensure that the back shall return to the same form after the book has been opened.
[Ill.u.s.tration: FIG. 39.]
To back the book, backing boards are placed on each side (leaving the slips outside) a short distance below the edge of the back (fig. 39).
The amount to leave here must be decided by the thickness of the boards to be used. When the backing boards are in position, the book and boards must be carefully lowered into the lying press and screwed up very tight, great care being taken to see that the boards do not slip, and that the book is put in evenly. Even the most experienced forwarder will sometimes have to take a book out of the press two or three times before he gets it in quite evenly and without allowing the boards to slip. Unless the back has a perfectly even curve when put in the press for backing, no amount of subsequent hammering will put it permanently right.