Roger Payne saw and liked the natural grain of goat skin, or, as we may now call it, morocco. But he found that in many cases he could get a better impression from his very delicately cut stamps in Russia leather. Here, however, he was restricted to one colour, and his favourite colour, a neutral green, could only be procured in morocco. So he ironed the morocco to flatten its natural hills and dales, and produced something like what is now called “crushed” morocco. Payne’s smooth morocco is, however, not quite our modern “crushed”; it is smoother, because now we “grain” our leather strongly before crushing it, whereas Payne ironed his without first increasing its natural grain by artificial means. Morocco is often badly injured by the ironing being done with irons that are too hot.
But Payne went a step farther. No doubt he experimented much with morocco, and it is likely enough that before endeavouring to smoothen out his skins he wetted them thoroughly. If he wetted a fine skin of morocco overnight and left it alone, perhaps doubling it or rolling it up, he would have noticed next morning that the natural grain had become much intensified, due to a slight shrinkage of the leather, and showed as a particularly effective breaking up of the surface. Some such chance led him to make definite experiments with a view to exaggerating the natural grain of morocco, and he very soon found out that if a damped skin was well rolled in one direction it assumed permanently what is now known as a “straight” grain. That is to say, the surface of the leather is lined in the same sort of way as a ploughed field is, but not quite so regularly. The ridges and furrows all run in one direction. Several of Payne’s bindings are bound in straight grain morocco, but judging from his own work, he never got any farther with his graining.
At a later time, I think towards the middle of the nineteenth century, it was found out that if the process of straight graining was carried out a second time at right angles to the first operation, the little straight furrows and ridges were broken up, and a surface was produced that consisted of a series of minute hillocks, like a field that has been harrowed, and this is known as a “pin-head” grain. Both these grainings improve the strength of the leather, as it contracts after the wetting and also the wear falls on the tops of the ridges or hillocks before it reaches the body of the leather.
French binders have always preferred smooth or crushed morocco for their bindings, as it is easier to gild upon. Morocco is sensitive to damp, and if affected it quickly betrays it by giving out the strong scent of goat which is normally quite absent.
Two new leathers have been recently put upon the market as rivals of morocco: one of these is seal skin and the other the skin of the sea-lion.
Seal skin is finished in the same way as morocco and looks very like it, but it is, I think, not so good. It is softer, more full of oil and has a peculiar, almost fishy, smell. The softness of seal leather makes it unfit for binding books that are likely to have much hard wear, but the oiliness is probably its worst fault, as books standing next to it are apt to be stained. But it is undoubtedly a good-looking and useful leather, and if it can be put upon the market at a less cost than morocco it is sure to have a considerable vogue. Sea-lion skin is only fit for use on big books; it is very strong and is curiously ridged in large ridges. It has the same oiliness that seal has, but not in so marked a degree.
There are, of course, several other leathers in which books have been bound as curiosities, and these are generally noted in some way; a book in the British Museum is lettered outside “Kangaroo,” and manuscript notes are in others telling us in what strange materials they are covered. Fish skin, known as shagreen, has sometimes been used for bindings; it is very strong but inelastic, and soon goes at the joints. In the seventeenth century it was largely imitated in calf, stamped with a grain.
Perhaps the most curious leather in which any book can be bound is human skin. Such treasures are by no means unknown. It is said that a friend of Camille Flammarion the French writer, possessed beautiful shoulders, and that when she died she bequeathed her skin to him as he had always admired it. He had the skin tanned and used some of it for a binding of one of his own books, “Ciel et Terre.” There are other examples in private ownership, but so far as public libraries are concerned the only instance I know of is now in the Carnavalet Library at Paris. It is a copy of the Constitution of 1793, and is bound in the skin of one of the revolutionaries who was killed at the time. The skin was tanned at Meudon. Human skin, undyed, looks like thick calf, and it is most difficult to get entirely rid of the hair.
It is to be regretted that of late years the desire for beautifully coloured leathers has induced the need for much treatment before the dyes, mostly aniline, could be properly applied. In the course of this treatment there has been an undue use of sulphuric acid, and the presence of this acid is fatal to the lasting qualities of any leather. Attention has, however, been drawn to the evil from authoritative sources, and now sound leathers can be obtained, and it is to be hoped that the public will second the endeavours of the committee appointed by the Society of Arts by always insisting on the use of sound and certified leather to bind their valuable books in.