CHAPTER II

METHODS OF WORKING IN LEATHER

TRACING THE DESIGN ON THE LEATHER

In this chapter the different processes which may be used in the decoration of leather will each be described in turn.

The preliminary operation of tracing the design on the leather is however common to them all.

The design should in the first instance be drawn on fairly thick tracing-paper or architect’s linen. This should then be fixed on the leather in such a way that it does not move during the transfer of the design, but so that it is possible to lift it to ascertain the progress of the work. It will be found convenient to fold the edge of the tracing-paper over the top edge of the leather and fix it with seccotine.

The leather must be wet in order to take the impression of the tracing. A soft, slightly damp sponge is passed several times evenly over the whole surface; if only a part of the leather were wetted an aureole would form round that part and would leave a permanent mark. When the leather has once been wetted all over there is no further fear of this, and it may then be damped again in parts when necessary. Practice alone will make it possible to judge accurately the degree of saturation that each skin requires to bring it into a fit condition for working on; speaking generally, the water should have penetrated the leather so that the pressure of the tool will not bring it back to the surface. Neglect of this rule might result in staining the leather.

[Illustration: FIG. 1.——TRACING-POINT]

The design is transferred to the leather by means of a metal tracing-point (Fig. 1). An agate or ebony point, or an exceedingly hard 6H graphite pencil, may also be used for the purpose. The pencil possesses the additional advantage that it can be given a very fine point where an extra thin and sharp outline is required. Doubling the outline by going over it twice should be avoided. From time to time the tracing-paper or linen should be raised to see that the design is being well marked on the leather. The outline should be dark; when it comes light it is a proof that the leather is too dry and requires damping again.

INCISING THE LEATHER

This being the first operation in working thick leather by carving, engraving and modelling, it will be dealt with before passing to the different processes peculiar to these methods of decoration. The incising is done after the design has been traced. There are numerous incising knives for the purpose which vary in shape and are manipulated in different ways; no one of them can be specially recommended as notably superior to the rest, and the artist should choose the one with which he feels most likely to succeed. The knife illustrated in Fig. 2 is used with a downward movement and is held——as shown in Fig. 3——very short, so as to obtain a sufficient purchase over the blade which is guided by the middle finger. The knife illustrated in Fig. 4 is used upwards. Fig. 5 shows the manner in which it should be held to produce a vertical cut. It will be found of great assistance in making a good firm cut to guide the right hand with the left hand as in Fig. 5. When curved lines are to be cut, the left hand must be used to turn the leather so as to present it in the most favourable position for the operation of the blade. The third knife (Fig. 6) is held like a graver with the handle supported against the palm of the hand and is pushed forward (Fig. 7). It is useful in cutting curved lines over a large surface. The depth of the incision should vary according to the effect to be produced by the subsequent operation, but it should never exceed a third of the thickness of the skin.

[Illustration: 2. CASKET COVERED WITH STAMPED LEATHER, _CUIR BOUILLI_. GERMAN, 14TH CENTURY.]

[Illustration: FIG. 2, FIG. 3.——INCISING KNIFE USED DOWNWARDS LIKE A PENCIL]

Thin skins should rarely be cut, and, if they are cut, the incision should barely penetrate the surface. On ox-hide the depth of the cut may be considerable without danger of impairing the strength of the leather.

[Illustration: FIG. 4, FIG. 5.——INCISING KNIFE USED UPWARDS]

When the leather is to be modelled in high relief, the design should be well separated from the background in the cutting process. The incision should also be deep when the outline is to be accentuated afterwards with a tool called an “opener” (Fig. 9) to produce an effect like the leading in stained glass.

Should it be desired to raise and turn up the edge of the leather to simulate a leaf, petal, or piece of ribbon detached from the background, the knife must be held slanting, as in Fig. 8, so as to make an almost horizontal cut.

[Illustration: FIG. 6, FIG. 7.——INCISING KNIFE HELD LIKE A GRAVER AND PUSHED FORWARD]

However thick the leather may be, it is important that two lines should never be cut quite up to the point of intersection. For example, in cutting the outline of a leaf, the points of the indentations should be left uncut to avoid the tendency of the part within the angle to project and turn back. Sufficient impression can be obtained with the modelling tool to give a finished effect to these points.

[Illustration: FIG. 8.——EXECUTING A SLANTING CUT WHEN THE EDGE OF THE LEATHER IS TO BE SUBSEQUENTLY TURNED UP]

The incision must be clean and sharp, and absolutely vertical, except where it is made slanting for the purpose described above.

[Illustration: 3. COFFRET COVERED WITH LEATHER, INCISED, COLOURED AND GILT. FRENCH, 14TH CENTURY.]

CUT OR ENGRAVED LEATHER

[Illustration: FIG. 9.——OPENER FIG. 10.——ENLARGING THE OUTLINE WITH THE OPENER]

Leather with flat decoration in outline of even thickness is called cut, or engraved leather. The tool used to enlarge and accentuate the outline is called an opener. It is like a straight modeller broadened in the centre and with a blunt point (Fig. 9), or a small blade with the point cut off square and the angles rounded. When the leather has been well wetted and the water has thoroughly soaked in, the end of the opener is inserted in the incision and pushed along it with a very slight and gentle gliding movement. The broader part of the opener will act as a wedge and widen the cut evenly. Openers can be had in various sizes to produce lines of different width. When the design is to be modelled afterwards, an opener should be used which broadens on the right side only; held slightly slanting, it will press down the outside edge of the incision which is to be sunk into the ground. Fig. 10 shows the manner of holding the tool; it should be worked backwards and forwards to make sure that the edges are evenly parted. The left hand may help to guide the point to prevent it from slipping off the line.

[Illustration: FIG. 11.——SLANTING CUT]

[Illustration: FIG. 11a.——SHOWING THE DIFFICULTY OF RAISING THE INNER EDGE (A)]

To be able to accomplish satisfactorily this operation of opening the outline, it will be found that the incision must be absolutely vertical. Supposing it to have been made slanting as in Fig. 11, it will be easy to sink the outer edge (B) into the ground, but when it comes to raising the inner edge (A) an excess of material will be encountered which will offer stubborn resistance to being raised in a direction contrary to that of the incision (Fig. 11a). The opener should not be moved at too great an angle in the incision as the point, though blunt, may yet be sharp enough to cut and spoil the modelling by raising the surface of the leather.

After it has been outlined, the leather may be further decorated by variously tinting the parts within the lines, if the style of the design will admit of such treatment; an effect similar to leather mosaic is thus produced. (See