SIZING
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.
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:—