# The Art of Bookbinding/Chapter 22

CHAPTER XXII.
Calf Colouring.
Although coloured calf-skins may be bought almost as cheaply as smooth calf (the term given to uncoloured ones), yet there are so many reasons why coloured calf should not be used, that I give such instructions as will enable any one to colour, sprinkle, and marble his own leather.
The skins may, however, be procured already sprinkled or marbled at most leather shops. This plan of sprinkling and marbling the whole skin is good enough for cheap or ​half-bound work, but for extra work it is far better to sprinkle, marble, or otherwise colour the leather when on the book. Hand-colouring is coming again into use, and by degrees getting known more and more throughout the trade; but a great many secrets in the art have been lost. Before giving the names of the chemicals to be used, I must give a general caution, that if any acid be used on the leather, it is essential to wash as much as possible of it out with water immediately after it has done its work, or after a few months the surface of the leather will be found to be eaten away and destroyed. It is a fault of some of our binders at the present day, that if they use any chemical, either on their leather or on their paper, they are not satisfied to use their acid weak, and allow it to do its work slowly, and when the proper moment has arrived stop its further action, they frequently use the acids as strong as possible, and, either to save time or through ignorance of their chemical properties, do not wash out the residue. The consequence is, the leather or the paper rots. In order to avoid this, I will not recommend any chemicals that will destroy the leather, but give instructions for harmless preparations, by the use of which as great a variety of different styles may be executed as will, I trust, satisfy any reasonable expectation.
Black.—Sulphate of iron or copperas is the chief ingredient in colouring calf black. Used by itself, it gives a greyish tint, but if a coat of salts of tartar or other alkali be previously used it strikes immediately a rich purple black. The name copperas is probably from the old and mistaken idea that the crystals contain copper. They have a pale greenish blue colour. It can be purchased at the rate of one penny per pound from any drysalter.
1. Into a quart of boiling water, throw a $^1$⁄$_4$-lb. of sulphate of iron, let it re-boil, and stand to settle, and then bottle the clear liquid for use.
​2. Boil a quart of vinegar with a quantity of old iron nails or steel filings for a few minutes. Keep this in a stone jar, and use the clear liquid. This can from time to time be boiled again with fresh vinegar. An old iron pot must be kept for boiling the black.
Brown.—1. Dissolve a $^1$⁄$_4$-lb. of salts of tartar in a quart of boiling water, and bottle it for use.
This liquid is mostly used for colouring; it has a very mellow tone, and is always used before the black when a strong or deep colour is required. It is poisonous, and must not be used too strong on the calf or it will corrode it.
2. For a plain brown dye, the green shells of walnuts may be used. They should be broken as much as possible, mixed with water, and allowed to ferment. This liquid should then be strained and bottled for use, A pinch of salt thrown in will help to keep it. This does not in any way corrode the leather, and produces the best uniform tint.
Yellow.—1. Picric acid dissolved in water forms one of the sharpest yellows. It is a pale yellow of an intense bitter taste. It must not be mixed with any alkali in a dry state, as it forms a very powerful explosive compound. It is a dangerous chemical and should be carefully used. It may be bottled for use.
2. Into a bottle put some turmeric powder, and mix well with methylated spirit; the mixture must be shaken occasionally for a few days until the whole of the colour is extracted. This is a very warm yellow, and produces a very good shade when used after salts of tartar.
For all the following, a preparation or ground of paste-water must be put on the calf, that the liquids may not sink through too much. The calf must be paste-washed all over equally, and allowed to get thoroughly dry. It will then be ready for the various methods. Perhaps to wash it over night and let it stand till next morning will ​be the best and surest plan. It matters very little whether the calf is on the book or in the skin.
Sprinkles.—There are so many sprinkles, that it would be useless for me to enumerate a number, they are all worked in the same manner, by throwing the colour on finely or coarsely, as it may be wanted light or dark.
Presuming that the paste or ground-wash be thoroughly dry, take liquid salts of tartar and dilute with cold water, one part salts to two of water, in a basin; wash the calf with this liquid evenly, using a soft sponge. The calf will require the wash to be applied two or three times, until a proper and uniform tint be obtained. Each successive wash must be allowed to get thoroughly dry before the next be applied.
The next process will be to sprinkle the book, with the boards extended or open. Two pieces of flat wood, about three feet long, four inches in width, and half an inch thick, will be found very useful for supporting the book. These rods must be supported at each end, so that the book may be suspended between them, with the boards resting on the rods nearly horizontally. Now put into a round pan some of the copperas fluid, and into another some of the solution of salts of tartar. Use a pretty large brush for each pan, which brush must be kept each for its own fluid. The sprinkling may be commenced. The brushes being well soaked in the fluids, should be well beaten out, using a piece of broomstick or a hand pin to beat on before beating over the book, unless a coarse sprinkle is desired. Whilst beating over the book, the hands should be held up high, and also moved about, so that a fine and equal spray may be distributed; and this should be continued until the desired depth of colour is attained.
This may be varied by putting some geometrical design, cut out of thin mill-board, on the cover; or if the book is on any special subject, the subject itself put on the cover ​will have a very pretty effect, and may be made emblematical. A fern or other leaf for botanical work as an instance. The sprinkle must in these cases be very fine and dark for the better effect. The leaf or design being lifted from the cover when the sprinkle is dry, will leave the ground dark sprinkle with a light brown leaf or design. Cambridge calf is done in this way by cutting a square panel of mill-board out and laying it on the sides. The square on the cover may be left brown or may be dabbed with a sponge.
Marbles.—As the success of marbling depends upon the quickness with which it is executed, it is important that the colours, sponges, brushes and water, should be previously disposed in order and at hand, so that any of them can be taken up instantly. Another point to which attention must be directed is the amount of colour to be thrown on, and consequently the amount that each brush should contain. If too much colour (black) is thrown on, the result will be an invisible marble, or, as I once heard it expressed by a workman, "it could not be seen on account of the fog;" if too little, no matter how nicely the marble is formed, it will be weak and feeble.
Marbling on leather is produced by small drops of colouring liquids, drawn, by the flowing of water down an inclined plane, into veins and spread into fantastic forms resembling foliage—hence, often called tree-marble. It is a process that requires great dexterity of hand and perfect coolness and decision, as the least hurry or want of judgment will ruin the most elaborate preparation.
To prepare the book paste-wash it evenly all over, and to further equalize the paste-water, pass the palm of the hand over the board after washing it. When dry, wash over with a solution of salts of tartar two or three times to get the desired tint. When dry, glaire the whole as even as possible, and to diminish the froth that the sponge may ​occasion, put a few drops of milk into the glaire. Again allow it to dry thoroughly. Put some fresh copperas into a pan, and some solution of salts of tartar into another, and soak each brush in its liquid. Place the book upon the rods, the boards extending over and the book hanging between. Should it be desired to let the marble run from back to foredge the back must be elevated a little, and the rods supporting the boards must be level from end to end. If the marble is to run from head to tail, elevate the ends of the rods nearest to the head of the book. The elevation must be very slight or the water will run off too quickly.
Place a pail of water close at hand, in it a sponge to wash off; and a bunch of birch to throw the water with. A little soda should be added to soften the water. Charge each brush well, and knock out the superfluous colour until a fine spray comes from it. A little oil rubbed in the palm of the hand, and the brush well rubbed into it, will greatly assist the flow of colour from the brush, and also prevent the black colour from frothing. Throw some water over the cover in blotches with the birch, just sufficient to make them unite and flow downwards together. Now sprinkle some black by beating the black brush on a press pin, as evenly and as finely as possible. When sufficient has been thrown on, beat the brown in like manner over the extended boards. When the veins are well struck into the leather, sponge the whole well with clean water. Have no fear in doing this as it will not wash off. Then set the book up to dry.
Tree-marbles.—The cover is to be prepared and sprinkled in the same manner as stated in marbling; the boards, however, must be bent a little, and a little water applied by a sponge in the centre of each board to give the necessary flow of water; when the water is thrown on, it will flow towards the centre or lowest part of the boards, and when the sprinkle is thrown on, a tree, as it were, will be ​formed. The centre being white forms the stem, and from it branches will be formed by the gradual flow of the streams of water as they run down.
For marbling, every thing must be ready at hand before any water is thrown on, so that the water may not have time to run off before the colour is applied. The water must ran at the same time that the spray is falling, or a failure will be the result.
It has been said that marbling was discovered by an accident; that a country bookbinder was sprinkling some books, when a bird, which was hung up in the shop, threw or splashed some water down on his books; the water running, took some of the colour with it and formed veins. Liking the form it gave, the workman improved upon it and thus invented marbling. There is, however, no doubt that it had its origin in Germany.
Tree calf seems to be coming into general use again, and to meet the demand for cheapness, a wood block has been cut resembling as closely as possible one done by the water process, and blocked in black on the calf; but, as might have been expected, it has not found much favour.
Dabs.—This is a process with a sponge, charged with the black or the brown liquid, dabbed on the calf either all over the cover or in successive order. Give the proper preparation to the calf, and be very careful that the ground tint of brown be very even. Take a sponge of an open nature, so that the grain is pleasant to the eye; fill it with black and squeeze out again, now dab it carefully over the calf. Repeat the operation with another sponge charged with brown. Cat's paw, French dab, and other various named operations all emanate from the sponge. When done properly this has a very good effect, and gives great relief to the eye when placed with a number of other books.
All these marbles and sprinkles require practice, so that ​a first failure must not be regarded with discouragement. When one's hand has got into the method with these two or three colours it is astonishing how many different styles may be produced. In all this manipulation a better effect is obtained if a yellow tint be washed over the leather after the sprinkle or marble has been produced. Again, by taking coloured calf and treating it in the same manner as white, some very pleasant effects are brought out; and when the colours are well chosen the result is very good. Take for instance a green calf and marble a tree upon it, or take a light slate colour and dab it all over with black and brown.
In all operations with the copperas care must be taken that it does not get on the clothes, as it leaves an iron stain that cannot be easily got rid of. Keep a bason for each colour, and when done with wash it out with clean water. The same with the sponges: keep them as clean as possible; have a sponge for each colour, and use it only for that colour. A piece of glass to put the sponges on will be of great use, and prevent the work-table or board from catching any of the colour. A damp book or damp paper laid on a board that has been so stained will most probably be damaged, even though it has waste paper between the work-board and book. No amount of washing will ever take away such a stain.
When the book has been coloured, the edges and inside are to be blacked or browned according to taste, or in keeping with the outside. The book is then ready for finishing.
Some very good results may be obtained if the binder, using coloured calf of a light brown, treats it as if it were white calf, marbling with the usual colours; or a yellow calf, splashing it all over with salts of tartar only, the boards being placed in a slanting direction to allow the colour to gently run down.
​Or the whole of a cover may be blacked with tartar and copperas, then with a diluted solution of acid it may be sprinkled, this will give grey-white spots on black or slate ground: if, after washing, the cover be sponged over with some colouring liquid, such as analine dyes, the spots will be of the colour used.
I do not give many methods or receipts for producing colours for calf, because, as before stated, the introduction of fancy calf has rendered obsolete the old-fashioned way of boiling and preparing the different woods for making colours, and the above will be found useful for colouring calf in many different ways.