The Decoration of Leather / From the French of Georges de Récy

by Georges de Récy

MODELLED LEATHER WITH PUNCHED BACKGROUND

When the leather has been cut before

being modelled, the punch completes the work of the modeller in sinking the outer edge of the incision into the background. To do this perfectly, the edge of the punch must be placed very exactly against the outline of the raised design; the handle should be held slanting slightly to the left in working; extra pressure will thus fall towards the right on that part which, in spite of having been sunk by the modeller, will always show a tendency to rise if the punch be used too flat upon the surface.

A hammer, though useful in working certain punches which depend upon being deeply impressed to produce a good effect, requires great sureness of hand when used as described above, to prevent overstepping the limits of the outline, and punches in wooden handles are much to be preferred for this work. Too deep an impression is avoided by their use, and, by guiding the end of the punch with the left hand, it can be placed more surely in the right position and worked by the steady pressure of the wrist. (Fig. 16.)

The most useful punches are those producing a powdered or a very small check pattern. With these there is no need for the impressions to be arranged in any regular order; it is indeed better that they should slightly overlap so that no part of the ground is left out. The effect of some punches is dependent on their arrangement in combination; others can be arranged independently to form a semis—a pattern made up by the repetition of some given figure at intervals.

Wheels, either plain or having a more or less broad surface engraved with any kind of pattern (such as a check diaper, pearling or arabesques), are used for outlining or for continuous patterns, or for producing imitations of shagreened leather.

An excellent effect can be obtained by varnishing the parts depressed by the punch to make the colour adhere, and then painting them with gouache or bronzes. By

rubbing the leather afterwards with a woollen cloth, the colour or bronze is easily removed from the unvarnished modelling.

PYROGRAVURE

FIG. 16.—USING A HAND PUNCH

The tools employed in pyrogravure are based on the same principle as the instrument for thermo-cautery in surgery. The apparatus in most general use consists of a platinum point mounted in a hollow metal handle connected by a rubber tube with a pear-shaped rubber

blower. This blower serves to inject through a tube the carburetted air from a small benzine reservoir attached to it. The incandescence of the point is maintained by this constant injection, and the lines are burnt more or less deeply according to the degree of incandescence, and the pressure applied. The great difficulty is to keep the line of even thickness throughout. The points are to be had of different shapes according to the effect desired. Some are pierced at the end, so that the carburetted air escaping leaves a mark on the leather similar to that which would be produced by a hot iron grazing its surface. In this way a brown tint is obtained varying in darkness in proportion to the proximity of the point to the leather.

6. Blind-stamped Morocco binding with gilt roundels and coloured cameo design. Celsus. De Medicina. Venice, 1477. Italian, 15th Century.

There are also rather large blowers which are worked automatically by compressed air, while others have a pedal action like a sewing machine.

It would be difficult to explain the many ways of handling the point so as to obtain different effects; it should, however, always be held slightly inclined to the right. It is shaped like an eagle’s beak, so that by using the point alone, fine lines of more or less depth are obtained, and by inclining it more to the right the rounded part will burn a larger surface of the leather. Very deep hollows can be made with the point highly heated. Pyrogravure is also an efficient way of depressing the ground work of thick leather when the point is worked with repeated touches over the surface. With a light hand and an accurate knowledge of the degree of heat required to produce fine lines, a skilful artist is able to draw with the point as if it were a pen.

The left hand plays a very important part in the process by controlling the injection of carburetted air through the blower, and thereby regulating the heat of the point. When the incandescence is automatically produced, equal facility in varying the degree of heat according to the requirements of the work is not possible.