Just as certain kinds of leather are difficult to treat, so also are old, long-stocked skins. If the finisher knows that such a piece of leather lies before him, he ought to rub it down on the raw side with best olive oil; it will thus receive a subst.i.tute for the lost natural fatty matter and become more supple. This oiling, of course, is only practicable with dark leathers, as light leathers nearly always become darker. A skin so treated should be rolled up and laid aside for a few days.

At any rate, such a defective leather is improved by a previous washing with size, no matter whether it be made from vellum, gelatine, or glue.

It must not, however, be made from the commonest kinds of glue, as these make the leather dull.

Vellum cuttings, or gelatine, are soaked overnight in water sufficient to cover, and next day dissolved in a sort of glue-pot. This sizing must be used very thin and should not be quite cold. In using ordinary glue, two drops of medium strength to about three table-spoonfuls of warm water will suffice.

Many finishers prefer thin paste water as a size, with which they coat the whole surface; personally, however, I would only recommend it for unpolished calf--but here there is a real necessity for it. In this case it is liberally laid on in large sweeps with a sponge--not new, and free from grit--and then well rubbed into the pores of the leather with the ball of the hand. The surplus is quickly washed off with clean water.

Large surfaces left plain are also washed with gum tragacanth, because this sizing leaves no lines behind. About 10 grammes of tragacanth to 1/4 litre water are soaked in a vessel, and after swelling it is well stirred. This solution is also laid on with a sponge, but is not rubbed in, neither is it subsequently washed off.

These two methods of sizing will be found sufficient to meet all cases.

There are certain materials that do not allow the use of a liquid sizing, particularly silk and velvet. The latter is no longer finished by hand, and even blocking velvet is now considered bad style.

For gold tooling on such materials gilding powder is used; it is to be had either white or yellow, but for hand tooling the white only is required.

Although no exact rules can be given for determining the temperature of the tools used upon the various materials, yet we must try to give a general rule for each kind.

We will use the following terms to distinguish the different degrees of heat: Lukewarm, _i.e._, not the slightest hissing when tested; medium, _i.e._, just on the border of hissing; hot, slightly hissing. In the following group the method of sizing is repeated, and a scheme for the approximately exact temperature of the tools is given.

Cloth, goat-skin, and marbled leather (without previous sizing, white of egg): medium heat.

Sheep-skin and lamb-skin (glue size, white of egg): medium heat. Calf (white of egg): hot.

Morocco goat (without sizing, white of egg): medium heat.

Morocco, Levant morocco, crushed morocco (glue size--painted in, white of egg): lukewarm.

Pig-skin, Russia, seal (without sizing, white of egg): lukewarm.

Mention has already been made of a wash of paste water for matt calf. As a rule, the whole surface is washed with this preparation, as it is thereby rendered less liable to finger marks. In the very best shops there is still another method. The leather is washed down with tragacanth and the previously impressed design picked out with white of egg and quickly tooled with tools medium to hot.

Vellum requires a special treatment. On the day before it is to be finished in gold it is washed with alum solution and, for gold tooling, sized with undiluted white of egg and tooled lukewarm.

When tooling is done with powder it is dusted on by means of a powder-box, over which is stretched some thin material, and tooled lukewarm.

The great convenience in the use of powder induces many binders to adopt it for leather and cloth also. This practice is objectionable, and the conscientious finisher will always avoid it. It may be excused when a name has to be printed on a Prayer-book or similar article in a hurry, or when an article is already varnished, as powder in such a case is very convenient and satisfactory, but under any other conditions it is a sign of incompetence.

Tooling upon powder on leather looks very gritty and unsightly after having undergone many changes of temperature, as the latter greatly affects this material. Its brightness vanishes entirely--a thing that never happens when white of egg has been used.

It must still be observed that tooling with lukewarm tools must be done slowly, and with hot tools quickly. Nearly all inexperienced finishers use too hot tools.

Fig. 82--Leather binding with fern motive done in the Dusseldorf Technical School.

So far, we have dealt with the preparation for finishing and tooling with a roll. Besides this tool there are fillets, gouges, and dies, all nearly the same, being dies, and only differing in shape. Nearly all beginners are unreasonably afraid to use the gouge. Any one able to use the roll properly will have little difficulty with the gouges. A genuine technical difficulty does arise when only a small portion of a curve may be worked (which frequently happens) on account of its having to be joined to another. Moreover, the joining of one curve to another must not be seen.

Every single gouge of the complete set (it should contain at least 20 pieces) forms the quarter of a circle. The gouges are chosen according to the design, so that the tools placed thereon cover the outlined design exactly, and the tool numbers are noted on the designs so that they may be quickly and surely picked up when required for use.

The tyro is apt to select sizes too large and to print the curve sloping instead of perpendicular; this must be guarded against.

Double gouges are not easily used in the same way, as the joinings cannot be concealed; they may be used for making first outlines, which must be finished with single curves.

Fig. 83--Simple gold tooling on squares.

Faulty places must be done over and over again until the whole is perfect and brilliant and all the gold adhering.

Fillets are nothing more than long narrow dies of either simple or ornamental lines. It is the practice of the old school to widen the impression of narrow fillets by continuous rocking of the hand to right and left, as they are fond of doing when lettering with a type-holder.

This practice is fundamentally wrong. Work finished in this way will never show the quiet and uniform brilliance in the gold to be seen in work where the movement was only in the direction of the dies and fillets.

Besides tooling the front sides, the inside edges or squares are generally ornamented in extra work. A simple but very effective decoration for the edge consists of a line close to the edge of the board and also one close to the end paper and a connecting line at the corner; such an edge is previously polished with a burnisher. To do this the leather is slightly damped, the tool moderately heated--not hissing--and then polished with long even strokes.

Fig. 84--Design in gold for squares. Tools by F. Clement, Leipzig.

Figs. 85 and 86--Two designs in gold for squares.

With the help of rolls and dies, even richer decoration may be produced, and really artistic ornament designed and executed on the inside as well as on the outside cover. Such work, however, does not come within the limits of this treatise. We must be satisfied with giving a few ill.u.s.trations of the less elaborate designs. Rolls are very often used in finishing the edges, so as to fill up at once the whole width of the s.p.a.ce, and about this we must say a few words. Rolls with a pattern have, as is known, no notch, and therefore may be used for a run on of any length without a break. For smaller margins and cheap work the rolls are frequently run over each other. This saves time but it does not produce a nice effect, as the design is blurred at the point of crossing. It is better to lay the gold leaf on one side and to remove it exactly at the corner and then tool; the side next to it is now treated in exactly the same way, giving special attention to the removal of the leaf at the corner. The design is thus made to join together at the corners without crossing, because the roll will only leave its impression as far as the gold goes. For extra work, however, a die suiting the roll in width and design should be chosen, and leaving as much of the corners as the die will cover free from gold, the remainder of the surface is covered with the leaf and tooled. With a little skill, the roll can be taken up exactly where the gold leaf ceases. The edge is then cleaned with the gold rag and fresh gold laid on for the corner die and then tooled. By this method the design at the corner is correctly finished.

Figs. 87, 88, and 89--Three simple backs. T, d, B = t.i.tle; N, T = Sub t.i.tle.

Gold tooling on the back is more difficult on account of its convexity.

For this work the volume is placed in a little wooden press which finds a place upon the bench, or in a special contrivance which can be screwed to the bench.

Fig. 90--Type-holder with centre position.

To ensure good results in tooling the back, it is necessary that the work to be done should be accurately marked out beforehand. The bands are measured out by means of the dividers if they do not already show as raised bands. With a pointed folder draw this traced design accurately upon a strip of cardboard. Blind lines are made upon cloth before the latter has become quite dry; in other cases tool the first impression hot and vigorously, pick out the impression with white of egg, and then tool with lukewarm fillets. In making lines, the fillets may be drawn to and fro, whereby a great brilliancy will be produced. Gold lines or ornamental fillets are picked out with white of egg and then tooled in gold. For simple lines the gold is taken up from the cushion; for ornamental fillets the gold is carried to the back.

Lettering the back is an art in itself as regards the arrangement of the lines, but besides this it requires considerable practical experience.

The letters are composed and screwed up in the type-holder for printing.

The type-holder, with the letters, must never be placed over the heating stove, for in Germany letters made of lead are still most generally used, and these would melt very quickly if placed over the stove.

Moreover, the letters should be screwed up just tight enough to prevent their falling out. The heat expands them and they are then locked quite firmly enough in the type-holder.

In arranging the letters the following general rules should be observed:--

1.--Always use types from the same fount in a t.i.tle.

2.--For books printed in Gothic (black letter) type use Gothic letters; for books printed in Latin types use the same for lettering.

3.--All lines in a t.i.tle should be set either in lower case only or in caps. only.

4.--Gothic and Latin in a t.i.tle are inconceivable.

5.--Except for abbreviations, points are no longer used in the t.i.tles of books, not even at the end; neither is a comma placed after the author's name.

6.--Nowadays, a short line is always made under the author's name.

Figs. 91, 92, 93, and 94--Four backs tooled in the Dusseldorf Technical School.