The actual cutting proceeds as follows: Starting at some point where the surface of the key-block design has been oiled and made distinct, a shallow cut is made along one side of any form in the design, with the knife held slanting so that the cut slants away from the edge of the form. A second outer parallel cut is then made with the knife held slanting in the opposite direction from the first, so that the two cuts together make a V-shaped trench all along the line of the form. The little strip of wood cut out should detach itself as the second cut is made, and should not need any picking out or further cutting if the first two cuts are cleanly made. This shallow V-shaped trench is continued all round the ma.s.ses and along both sides of all the lines of the design. No clearing of the intervening s.p.a.ces should be attempted until this is done. It will be seen at once that the V-shaped cuts give great strength to the printing lines, so that a quite fine line between two cuts may have a strong, broad base (fig. 9). The depth of the cut would be slightly shallower than that shown in this diagram. In cutting fine line work a cut is first made a little beyond the line, then the cut is made on the line itself (fig. 10).
[Ill.u.s.tration: FIG. 9.--Knife cuts in section.]
[Ill.u.s.tration: FIG. 10.--Diagram of knife cuts.]
Where a very fine line is to be cut, especially if it is on a curve, the outer cut of the V trench should be made first, and then that which touches the line: there is thus less disturbance of the wood, and less danger of injuring the edge of the line.
When the V cut has been made outside all the lines, one proceeds to clear the intervening s.p.a.ces between the lines of the design by taking tool No. 1 (fig. 5). The large s.p.a.ces should be cleared first. The safest and quickest way is to make a small gouge cut with No. 1 round all the large s.p.a.ces close up to the first cut, then, with one of the shallower chisels, Nos. 5, 6, or 7 (fig. 5), and the mallet, clear out the wood between the gouge cuts.
For all shallow cuts where the mallet is not needed, the j.a.panese hold the chisels as shown in fig. 11. With practice this will be found a very convenient and steady grip for the right hand. It has also the advantage that the chisel can be held against the centre of the body and exactly under one"s eyes.
In the diagram (fig. 12), if the wood from A to A1 is to be cleared away, gouge cuts are made at _b_ and _b_1, then the s.p.a.ce between _b_ and _b_1 may be quickly cleared without risk to the edge of the form at A. When this rough work is done the little ridge between A and _b_ may be cleared with small round or flat tools, as is most convenient. But this final clearing should not be done until all the large s.p.a.ces are roughed out.
[Ill.u.s.tration: FIG. 11.--Method of holding gouge.]
[Ill.u.s.tration: FIG. 12.--Clearing of wood between knife cuts.]
The depth to which the s.p.a.ces must be cleared will depend on their width, as, in printing, the paper will sag more deeply in a wide s.p.a.ce than in a narrow one. In s.p.a.ces of half an inch the depth of the first V-cuts is sufficient, but the proportionate depth is about that of the diagram above. The small s.p.a.ces are cleared by means of small flat or round chisels without the mallet or the preliminary gouge cut: this is only needed where a large s.p.a.ce has to be cleared.
There remain now only the placing and cutting of the two register marks or notches for controlling the position of the paper in printing.
These are placed relatively to the design as shown in fig. 13.
The corner of the print fits into the notch at A, and one edge of the print lies against the straight notch at B.
The register marks may be even closer to the s.p.a.ce covered by the design, but must not actually touch it, as some margin of paper is necessary in printing: they should also be cut always on the long side of the printing block. It will be seen from the drawing on page 70 that these register marks correspond to the position of the thumb of each hand in laying the paper on the block for printing.
[Ill.u.s.tration: FIG. 13.--Position of register marks.]
[Ill.u.s.tration: FIG. 14.--Register marks.]
The corner mark, ABC, is made by cutting from A to B and B to C, with the knife held perpendicularly, and its flat side against the line, then the shaded portion is cut with a flat chisel, sloping from the surface of the block at AC to a depth of about 1/16 inch along AB and BC. The straight notch, EF, is similarly cut, first with a perpendicular knife along EF, and then the shaded portion is chiselled sloping down to the line EF.
[Ill.u.s.tration: FIG. 15.--Register marks (section of).]
In section the two register marks would be as above.
The register marks must be smoothly and evenly cut so that the paper, in printing, may slide easily home to its exact place.
When the design of the key-block and the two register marks have been cut and cleared, the trace of paper and paste on the uncut parts of the wood should be carefully washed off with a piece of sponge and warm water. The block is then finished and ready for use. The key-block, however, is only one of the set of blocks required for a print in colour, but the colour blocks are simpler and require, as a rule, far less labour.
The colour blocks are planned and established by means of impressions taken from the key-block. For this purpose the register marks are inked[2] for printing as well as the design on the block, and the impressions must include both. These impressions are taken on thin j.a.panese paper, but not necessarily the thinnest tissue. If the thinnest is used, it should be pasted at the corners to a sheet of stiffer paper for convenience in handling.
[2] The preparation of the ink for printing is described on p. 54.
It is then a fairly simple matter to take one of these key-block impressions and to make a plan of the various colour-blocks that will be required. These should obviously be as few as possible.
It is not necessary to provide an entire block for each patch of colour, but only the extent of surface required for each coloured portion of the print, as well as for its pair of register marks. Patches of different colour that are not adjacent to one another on the design of the print may be cut on the same block, provided they are not too close for free colouring of the block in printing. Each block also may be cut on both sides, so that there is considerable scope for economy in the arranging and planning of the colour blocks.
When the arrangement of the plan of colour has been simplified as far as possible, a new block is prepared as described above, and a sheet of thin j.a.panese paper (unsized) is cut large enough to cover the print design and its register marks. The clean surface of the new block is covered thinly with starch paste well rubbed into the grain, and while this is still wet an impression on the sheet of thin j.a.panese paper is taken of the entire key-block, including its register marks in black, and laid before it is dry face downward on the pasted surface of the new block. This should be done as already described on page 25. It should be rubbed flat with the printing pad and left to dry.
This operation requires careful handling, but it should be done easily and methodically, without any hurry.
Each side of the set of colour planks should be treated in the same way--a thin impression of the key-block and its register marks being laid upon each. It is advisable to paste down a freshly taken impression, each time, while the ink is still moist, for if these are allowed to dry, the shrinking of the paper causes errors of register.
When these new blocks are dry, the patch of colour to be cut on each surface should be clearly indicated by a thin wash of diluted ink or colour, but not so as to hide the printed key line.
The blocks may then be cut. A V-shaped cut is made round each form, as in the case of the key-block, and the clearing proceeds in the same way, but it is only necessary to clear a s.p.a.ce of about an inch round each form: the rest of the wood should be left standing. A section of the printing surface of a colour block would be as follows:
[Ill.u.s.tration: FIG. 16.--Section of colour-block. A. Colour ma.s.s. B. Depression. C. Surface of Plank.]
When the register marks corresponding to these colour forms have also been cut, and the paper washed off the blocks, the clear s.p.a.ces may be used for pasting down new key impressions for the smaller colour patches and their corresponding register marks. In this way one side of a colour plank may contain several different colour forms and sets of register marks. As a rule the different colour patches would be printed separately, though in some cases two colours may be printed at one impression if they are small and have the same register marks.
When the blocks have been cut and cleared it is advisable to smooth with sand-paper the edge of the depression where it meets the uncut surface of the wood, otherwise this edge, if at all sharp, will mark the print.
For any particulars about which one may be in doubt, the sets of blocks at South Kensington Museum or in the Print Room at the British Museum are available for examination. In one of the sets at the British Museum it is interesting to see the temporary corrections that have been made in the register marks during printing by means of little wooden plugs stuck into the register notches.
In nearly all cases the j.a.panese blocks were made of cherry wood, but planks of box are said to have been occasionally used for very fine work.
ERRORS OF REGISTER
However exactly the register marks may be cut in a new set of blocks, very puzzling errors occasionally arise while printing, especially if the planks are of thin wood.
Some of the blocks are necessarily printed drier than others. For instance, the key-block is printed with a very small amount of ink and paste. Other blocks may be even drier, such as the blocks which print small forms or details in a design. The blocks, however, which are used for large ma.s.ses of colour, or for gradated tones, are moistened over the whole or a large part of the surface of the block, and if the wood is thin, and not well mounted across the ends, the block soon expands sufficiently to throw the register out. If the block is not mounted across the ends there will also be a tendency to warp, and this will add to the errors of register. But if the blocks are of fairly thick wood, and well mounted, the register will remain very exact indeed.
Usually the key-block is printed first. If the subsequent blocks are not in exact register the error is noticeable at once, and slight adjustments may be made for its correction. But in cases where the key-block is printed last (as sometimes is necessary) each colour block must be tested before a batch of prints is pa.s.sed over it. For this purpose the first few prints of every batch should receive a faint impression of the key-block, so that the register of the colour impression may be verified before proceeding with the whole batch.
If these precautions are taken, and the entire set of blocks kept as nearly as possible in the same conditions of dryness or moisture, all difficulties of register in printing will be easily overcome.
When cutting a new set of blocks there is another possible source of error which needs to be carefully guarded against. Most of the work in designing a new print is necessarily spent in planning and cutting the key-block, which may occupy a considerable time, especially if other work has to be carried on as well. If new wood is used, or wood that has not been seasoned long indoors, it will dry and contract considerably across the grain before the work is finished. Then, if newer planks are prepared and cut up for the colour blocks, and impressions from the key-block are pasted down on them for cutting, it will be found that, as the newer wood of the colour-blocks goes on drying, it will shrink out of register, and the colour impressions will not fit the line perfectly.
It is easy to fall into this difficulty, but there is no danger of it if the planks from which the key-block and the colour-blocks are cut are all equally seasoned and are in the same condition.
CHAPTER V
Preparation of Paper, Ink, Colour, and Paste for Printing
PAPER
The paper made by the j.a.panese from the inner bark of young shoots of the mulberry and certain other plants of similar fibre is beyond all others the best for wood-block printing. It is in itself a very remarkable material, and is used in j.a.pan for a great variety of purposes, on account of the strength and toughness due to its long silky fibre.
Paper of good quality for printing may be obtained directly from j.a.pan, or through trading agents dealing with j.a.pan. A case of five reams would be the smallest quant.i.ty obtainable directly, but it is by far the cheapest and most satisfactory way of buying it. In smaller quant.i.ties the paper is obtainable through many of the dealers in artists"
materials. Several kinds of this paper are made, but unsized sheets of a quality similar to the print on page 95, and a thin j.a.panese tissue paper are the two kinds required for printing in colour.