“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.
MENDING
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.