The gravers and tint-tools used for engraving on a plane surface are straight at the point, as are here represented, Figs. 14 and 15; but for engraving on a block rendered concave in certain parts by lowering, it is necessary that the point should incline slightly upwards as in Fig. 14. The dotted line shows the direction of the point used for plane surface engraving. There is no difficulty in getting a tool to descend on one side of a part hollowed out or lowered; but unless the point is slightly inclined upwards, as is here shown, it is extremely difficult to make it ascend on the side opposite without getting too much hold, and thus producing a wider white line than intended.
Gouges and Chisels, A to E, Fig. 16. - Gouges of different sizes are used for scooping out the wood towards the centre of the block; whilst flat tools, or chisels, are chiefly employed in cutting away the wood towards the edges, about 1/8 inch below the subject. The gouge is similar to an ordinary carpenter's gouge, except that it is solid, being a round bar, with the end ground off at an angle. The other articles required are: - a sandbag, on which to rest the block whilst engraving it; an agate burnisher and a dabber, which are used for taking proof-impressions of the wood-cut; an oil stone, and an eye-glass with shade.
Engravers on copper and steel, who have much harder substances than wood to cut, hold the graver with the forefinger extended on the blale beyond the thumb, Fig. 17, so that by its pressure the point may be pressed into the plate. As boxwood, however, is much softer than these metals, and as it is seldom of perfectly equal hardness throughout, it is necessary to hold the graver in a different manner, and employ the thumb at once as a stay or rest for the blade, and as a check upon the force exerted by the palm of the hand, the motion being chiefly guided by the forefinger, as is shown in Fig. 18. The thumb, with the end resting against the side of the block, in the manner just represented, allows the blade to move backwards and forwards with a slight degree of pressure against it, and in case of a slip, it is ever ready to check the graver's progress. This mode of resting the thumb against the edge of the block is, however, only applicable when the cuts are so small as to allow the graver, when thus guided and controlled, to reach every part of the subject.
For large coarse cuts, such as are often used for trade purposes, sycamore and pear tree may be employed, but they are too soft and irregular in the grain to bear fine work. Boxwood, either English, American, or from the Levant, is the favourite material; it should be of a light straw yellow colour, free from black or white spots, or red streaks, as these indicate a soft wood, which crumbles away under the graver. The small wood is generally tolerably free from blemishes. When a large cut is wanted, if a block of the required size is not at hand, several smaller blocks are sometimes bolted together. The blocks are cut a trifle thicker than the height of type, about an inch; they are then planed, brought to a very smooth surface, and gauged to the exact height of type. These blocks should be kept for some months until they are properly sea-oned.
The polished boxwood will not take the pencil without a slight wash is first laid on it. A thin wash of Chinese white mixed with water, some very fine Bath brick dust, or the white scrapings of glazed cardboard, mixed with water, and gently rubbed off when dry with the palm of the hand, gives a capital surface for the black-lead pencil. Make a tracing of the outline of the subject, place a sheet of transfer paper on the block, lay the tracing over it, and go carefully over every line with a sharp point. It must be remembered that the woodcut will be reversed when printed. The outlines must be corrected, and completed, by a hard sharp-pointed HHHH pencil; the tints may afterwards be filled in by a softer pencil, or thin washes of Indian ink, to show the effect of light and shade. Caution must be taken to use these washes sparingly, so as not to affect the wood. All parts of the block, not being cut, must be kept covered up, so as to preserve the drawing from injury, and the fine lines of the cut from being blunted or broken.
Smooth blue glazed paper is very good for this purpose, as it reduces the glare from the lamp.
When the engraving is finished, a proof may be taken in the following manner before blocking out the cut, that is, before the superfluous wood is cleared away; - rub down a little printers' ink on a slab till it is fine and smooth; take a little of this on a silk dabber, and carefully dab the block until sufficient ink is. left upon the surface, without allowing any to sink below it. Lay a piece of India paper on the block with about two inches margin all round; on this place a thin smooth card; rub this over with the burnisher, taking care not to shift the card or paper.
If a slip or mistake occurs in a woodcut, it may be remedied by the insertion of a plug. A hole must be drilled in the block; if the error is a small one the hole need not be deep, but if a large piece has to be inserted it must be deeper in proportion. A plug is cut, of a round taper shape; the small end is inserted in the hole, and the plug is driven down, without, however, using too much force. The top of the plug must then be cut off, and carefully rought to a smooth surface, level with the rest of the block; if this is not done, the plug will be visible on the print.
If the error to be remedied happens to be in a long line, a hole must be drilled at each end, and the wood between the two holes removed by small chisels, the hollow space being filled up in a similar way to that already described.