Bookbinding, and the Care of Books, by Douglas Cockerell

Chapter IV

Sizing — Washing — Mending


The paper in old books is sometimes soft and woolly. This is generally because the size has perished, and such paper can often be made perfectly sound by resizing.

Fig. 17.
Fig. 17.

For size, an ounce of isinglass or good gelatine is dissolved in a quart of water. This should make a clear solution when gently warmed, and should be used at about a temperature of 120° F. Care must be taken not to heat too quickly, or the solution may burn and turn brown. If the size is not quite clear, it should be strained through fine muslin or linen before being used. When it is ready it should be poured into an open pan (Fig. 17), so arranged that it can be kept warm by a gas flame or spirit lamp underneath. When this is ready the sheets to be sized can be put in one after another and taken out at once. The hot size will be found to take out a great many stains, and especially those deep brown stains that come from water. If there are only a few sheets, they can be placed between blotting-paper as they are removed from the size; but if there is a whole book, it is best to lay them in a pile one on the other, and when all have been sized to squeeze them in the “lying press” between pressing-boards, a pan being put underneath to catch the liquid squeezed out. When the sheets have been squeezed they can be readily handled, and should be spread out to dry on a table upon clean paper. When they are getting dry and firm they can be hung on strings stretched across the room, slightly overlapping one another. The strings must first be covered with slips of clean paper, and the sized sheets should have more paper over them to keep them clean.

Before sizing it will be necessary to go through a book and take out any pencil or dust marks that can be removed with indiarubber or bread crumbs, or the size will fix them, and it will be found exceedingly difficult to remove them afterwards.

When the sheets are dry they should be carefully mended in any places that may be torn, and folded up into sections and pressed. A long, comparatively light pressure will be found to flatten them better and with less injury to the surface of the paper than a short, very heavy pressure, such as that of the rolling-machine.

In some cases it will be found that sheets of old books are so far damaged as to be hardly strong enough to handle. Such sheets must be sized in rather a stronger size in the following way:— Take a sheet of heavily-sized paper, such as notepaper, and carefully lay your damaged sheet on that. Then put another sheet of strong paper on the top, and put all three sheets into the size. It will be found that the top sheet can then be easily lifted off, and the size be made to flow over the face of the damaged sheet. Then, if the top sheet be put on again, the three sheets, if handled as one, can be turned over and the operation repeated, and size induced to cover the back of the damaged leaf. The three sheets must then be taken out and laid between blotting-paper to take up the surplus moisture. The top sheet must then be carefully peeled off, and the damaged page laid face downwards on clean blotting-paper. Then the back sheet can be peeled off as well, leaving the damaged sheet to dry.

The following is quoted from “Chambers’ Encyclopædia” on Gelatine:—

“Gelatine should never be judged by the eye alone.

“Its purity may be very easily tested thus: Soak it in cold water, then pour upon it a small quantity of boiling water. If pure, it will form a thickish, clear straw-coloured solution, free from smell; but if made of impure materials, it will give off a very offensive odour, and have a yellow, gluey consistency.”


When there are stains or ink marks on books that cannot be removed by the use of hot size or hot water, stronger measures may sometimes have to be taken. Many stains will be found to yield readily to hot water with a little alum in it, and others can be got out by a judicious application of curd soap with a very soft brush and plenty of warm water. But some, and especially ink stains, require further treatment. There are many ways of washing paper, and most of those in common use are extremely dangerous, and have in many cases resulted in the absolute destruction of fine books. If it is thought to be absolutely necessary that the sheets of a book should be washed, the safest method is as follows:— Take an ounce of permanganate of potash dissolved in a quart of water, and warmed slightly. In this put the sheets to be washed, and leave them until they turn a dark brown. This will usually take about an hour, but may take longer for some papers. Then turn the sheets out and wash them in running water until all trace of purple stain disappears from the water as it comes away. Then transfer them to a bath of sulphurous (not sulphuric) acid and water in the proportion of one ounce of acid to one pint of water. The sheets in this solution will rapidly turn white, and if left for some time nearly all stains will be removed. In case any stains refuse to come out, the sheets should be put in clear water for a short time, and then placed in the permanganate of potash solution again, and left there for a longer time than before; then after washing in clear water, again transferred to the sulphurous acid. When sheets are removed from the sulphurous acid they should be well washed for an hour or two in running water, and then may be blotted or squeezed off and hung up on lines to dry. Any sheets treated in this way will require sizing afterwards. And if, as is often the case, only a few sheets at the beginning or end of the book have to be washed, it will be necessary to tone down the washed sheets to match the rest of the book by putting some stain in the size. For staining there are many things used. A weak solution of permanganate of potash gives a yellowish stain that will be found to match many papers. Other stains are used, such as coffee, chicory, tea, liquorice, &c. Whatever is used should be put in the size. To ascertain that the right depth of colour has been obtained, a piece of unsized paper, such as white blotting-paper, is dipped in the stained size and blotted off and dried before the fire. It is impossible to judge of the depth of colour in a stain unless the test piece is thoroughly dried. If the stain is not right, add more water or more stain as is needed. Experience will tell what stain to use to match the paper of any given book.

To remove grease or oil stains, ether may be used. Pour it freely in a circle round the spot, narrowing the circle gradually until the stain is covered. Then apply a warm iron through a piece of blotting-paper.

Ether should only be used in a draught in a well-ventilated room on account of its well-known inflammable and anæsthetical properties.

A very dilute (about one per cent.) solution of pure hydrochloric acid in cold water will be found to take out some stains if the paper is left in it for some hours. When the paper is removed from the solution, it must be thoroughly washed in running water. It is important that the hydrochloric acid used should be pure, as the commercial quality (spirits of salts) often contains sulphuric acid.

The following recipes are quoted from De l’organisation et de l’administration des Bibliothèques, par Jules Cusin:—

To remove stains from paper:— “Mud Stains. — To take away these kinds of stains, spread some soap jelly very evenly over the stained places, and leave it there for thirty or forty minutes, according to the depth of the stain. Then dip the sheet in clean water, and then having spread it on a perfectly clean table, remove the soap lightly with a hog’s hair brush or a fine sponge; all the mud will disappear at the same time. Put the sheet into the clear water again, to get rid of the last trace of soap. Let it drain a little, press it lightly between two sheets of blotting-paper, and finish by letting it dry slowly in a dry place in the shade.

Stains of Tallow, Stearine, or Fat. — To take away these stains cover them with blotting-paper and pass over them a warm flat-iron. When the paper has soaked up the grease, change it and repeat the operation until the stains have been sufficiently removed. After that, touch both sides of the sheets where they have been stained with a brush dipped in essence of turpentine heated to boiling-point. Then to restore the whiteness of the paper, touch the places which were stained with a piece of fine linen soaked in purified spirits of wine warmed in the water-bath. This method may also be employed to get rid of sealing-wax stains.

Oil Stains. — Make a mixture of 500 gr. of soap, 300 gr. of clay, 60 gr. of quicklime, and sufficient water to make it of the right consistency, spread a thin layer of this on the stain, and leave it there about a quarter of an hour. Then dip the sheet in a bath of hot water; take it out, and let it dry slowly.

“You can also use the following method, generally employed for finger-marks:—

Finger-marks. — These stains are sometimes very obstinate. Still they can generally be mastered by the following method:— Spread over them a layer of white soap jelly (savon blanc en gelée), and leave it there for some hours. Then remove this with a fine sponge dipped in hot water, and more often than not all the dirt disappears at the same time. If this treatment is not sufficient, you might replace the soap jelly by soft soap (savon noir), but you must be careful not to leave it long on the printing, which might decompose and run, and that would do more harm than good.”

Sheets of very old books are best left with the stains of age upon them, excepting, perhaps, such as can be removed with hot water or size. Nearly all stains can be removed, but in the process old paper is apt to lose more in character than it gains in appearance.


For mending torn sheets of an old book, some paper that matches as nearly as possible must be found. For this purpose it is the custom for bookbinders to collect quantities of old paper. If a piece of the same tone cannot be found, paper of similar texture and substance may be stained to match.

Supposing a corner to be missing, and a piece of paper to have been found that matches it, the torn page is laid over the new paper in such a way that the wire marks on both papers correspond. Then the point of a folder should be drawn along the edge of the torn sheet, leaving an indented line on the new paper. The new paper should then be cut off about an eighth of an inch beyond the indented line, and the edge carefully pared up to the line. The edge of the old paper must be similarly pared, so that the two edges when laid together will not exceed the thickness of the rest of the page. It is well to leave a little greater overlap at the edges of the page. Both cut edges must then be well pasted with white paste and rubbed down between blotting-paper. To ensure a perfectly clean joint the pasted edge should not be touched with the hand, and pasting-paper, brushes, and paste must be perfectly clean.

In the case of a tear across the page, if there are any overlapping edges, they may merely be pasted together and the end of the tear at the edge of the paper strengthened by a small piece of pared paper. If the tear crosses print, and there are no overlapping edges, either tiny pieces of pared paper may be cut and laid across the tear between the lines of print, or else a piece of the thinnest Japanese paper, which is nearly transparent, may be pasted right along the tear over the print; in either case the mend should be strengthened at the edge of the page by an additional thickness of paper. In cases where the backs of the sections have been much damaged, it will be necessary to put a guard the entire length, or in the case of small holes, to fill them in with pieces of torn paper. The edges of any mend may, with great care, be scraped with a sharp knife having a slight burr on the under side, and then rubbed lightly with a piece of worn fine sand-paper, or a fragment of cuttle-fish bone. Care must be taken not to pare away too much, and especially not to weaken the mend at the edges of the sheet. As a general rule, the new mending paper should go on the back of a sheet.

Sometimes it is thought necessary to fill up worm-holes in the paper. This may be done by boiling down some paper in size until it is of a pulpy consistency, and a little of this filled into the worm-holes will re-make the paper in those places. It is a very tedious operation, and seldom worth doing.

Fig. 18.
Fig. 18.

Mending vellum is done in much the same way as mending paper, excepting that a little greater overlap must be left. It is well to put a stitch of silk at each end of a vellum patch, as you cannot depend on paste alone holding vellum securely. The overlapping edges must be well roughed up with a knife to make sure that the paste will stick. A cut in a vellum page is best mended with fine silk with a lacing stitch (see Fig. 18).

Mending is most easily done on a sheet of plate-glass, of which the edges and corners have been rubbed down.

Last updated Friday, March 7, 2014 at 13:06