« PreviousContinue »
manner has been to confine the right arm close to the side, placing the fore finger of the left hand on the upper side of the tool when on the stone. This instrument is used for finishing the impersections discoverable in etchings, and exclusively in engraving writing. The scraper is a long triangular piece of steel, tapering gradually from the handle to the point; the three edges produced by this form, being sharpened on the oil-stone, are used for scraping off the roughness occasioned by the graver, and erasing erroneous lines. The burnisher is a third instrument of steel, hard, round, and highly polished, for rubbing out punctures or scratches in the copper. The oil stone has been already mentioned; to those may be added the needle or dry point for etching, and making those extremely fine lines which cannot be done with the graver. Cushions made of soft leather, and filled with fine sand, hence called sandbags, are required for the support of the plate in engraving, which, from their circular surface, permit the copper to turn with ease, and facilitate the cutting of those true curves composing the shading of most subjects. The oil rubber and charcoal are necessary for polishing the plate. Every thing depends upon the free use of the graver, therefore the utmost care must be taken to hold it properly, by preventing the interposition of the fingers between the graver and the plate, with the fore finger on the upper angle, which enables the artist to conduct it parallel with the substance engraved, thus preventing the point from entering deeply, and impeding the progress of the tool. To engrave well requires good materials, though those are nearly confined to two, the graver, and the best copper; the latter should be free from flaws, small punctures, well hammered to close the pores, and polished to such a degree as to be free from the slightest scratches. To trace the design intended for engraving accurately on the plate, it is usual to heat the latter sufficiently to melt white wax, with which it must be covered equally and thin, and suffered to cool; the drawing is then copied in outlines with a black-lead pencil on paper, which is laid with the pencilled side upon the wax, and the back rubbed gently with the burnisher, which will transfer the lead to the wax. The design must next be traced with an etching needle throug the wax on the copper, when, on wiping
it clean, it will exhibit all the outlines ready for the graver. The table intended for engraving on should be perfectly steady, and the sandbags placed equally firm in cutting of curved or undulating lines, the graver must be held still, or moved, to suit the turning of the plate with the left hand ; but when straight lines are intended, the plate is to be held stationary, and the graver urged forward with more or less pressure, according to the thickness of the line. Great care is necessary to carry the hand with such steadiness and skill, as to prevent the end of the line from being stronger and deeper than the commencement; and sufficient space must be left between the lines, to enable the artist, to make those stronger, gradually, which require it. The roughness or burr occasioned by the graver must be removed by the scraper, the lines filled by the oil-rubber, and the surface of the copper cleansed, in order that the progress of the work may be ascertained. If any accident should occur, by the slipping of the graver beyond the boundary required, or lines are found to be placed erroneously, they are to be ef. faced by the burnisher, which leaving deep indentings, those must be levelled by the scraper, rubbed with charcoal and water, and finally polished lightly with the burnisher. As the uninterrupted light of the day causes a glare upon the surface of the copper, hurtful and dazzling to the eyes, it is customary to engrave beneath the shade of silk paper, stretched on a square frame, which is placed reclining towards the room, near the sill of a window.
Such are the directions and means to be employed in engraving historical subjects : indeed, the graver is equally necessary for the completion of imperfections in etching, to which must be added the use of the dry point in both, for making the faintest shades in the sky, architecture, drapery, water &c. &c.
Engraving of . Mezzotintos differs entirely from the manner above described : this method of producing prints, which resemble drawings in Indian ink, is said by Evelyn, in his history of chalcography, to have been discovered by Prince Rupert, and was some years past a very favourite way of engraying portraits and historical subjects; of the former, the large heads by Fry are of superior excellence,
The tools required for this easy and rapid mode of proceeding are, the grounding-tool, the scraper, and the burnisher ;
the copperplate should be prepared as if
intended for the graver, and laid flat upon a table, with a piece of flannel spread under it, to prevent the plate from slip: ping ; the grounding-tool is then held perpendicularly on it, and rocked with moderate pressure backwards and forwards, till the teeth of the tool have equally and regularly marked the copper from side to side; the operation is afterwards repeated from end to end, and from each corner to the opposite ; but it is necessary to observe, that the tool must never be permitted to cut twice in the same place ; by this means the surface is converted into a rough chaos of intersections, which, if covered with ink and printed, would present a perfectly black impression upon the paper.
To transfer the design to be scraped, it is usual to rub the rough side of the plate with a rag dipped into the scraÉ. of black chalk, or to smoke it with
urning wax taper, as in the process for etching; the back of the design is then covered with a mixture of powdered red chalk and flake white, and laid on the plate through which it is traced ; particles of red, in the form of the outlines, are thus conveyed to the black chalk on the plate, which are to be secured there by the marks of a blunted point ; the process must then be carried on with the scraper, by restoring the plate in the perfectly light parts of the intended print to a smooth surface, from which the gradations are preserved by scraping off more or less of the rough ground , but the burnisher is necessary to polish the extreme edges of drapery, &c., where the free touch of the brush in painting represents a brilliant spot of light. The deepest shades are sometimes ctehed and corroded by aqua fortis, and so blended with the mezzotinto ground added afterwards, that there is nothing offensive to the eye in the combination.
Many proofs are required to ascertain whether the scraping approaches the desired effect, which is done by touching the deficient parts with white or black chalk, on one of the proofs from the original drawing, and then endeavouring to make the plate similar by further scraping, or relaying the ground with a small tool made for this particular purpose, where too much of the roughness has been effaced.
Engraving on Steel is confined to the cutting of punches, for the conveyance of any form a certain depth into that or any other metal, seals, and dyes, for impressing the designs of coins, medals, &c. on gold, silver, or copper, &c. The punches are engraved from models in wax made in relievo, and, when com: pleted, are tempered to that degree of solidity, which will bear the violent blows, without blunting the finest parts or breaking them, necessary to produce the ma: trix in the steel intended for striking of medals or coins, which must be heated to prevent such a disaster, and tempered again, for a similar reason to the preced. ing, after it is finished. There are several tools used in finishing of dyes, which are, gravers, chissels, and flatters; and many little punches for making ornamental borders and mouldings to coins and medals; the latter are always in greater relief than the former, and consequently more difficult to execute in perfection. Engraving on precious Stones is accomplished with the diamond or emery. The diamond possesses the peculiar property of resisting every body in nature, and, though the hardest of all stones, it may be cut by a part of itself, and polished by its own particles. In order to render this splendid substance fit to perform the operations of the tool, two rough dia. monds are cemented fast to the ends of the same number of sticks, and rubbed together till the form is obtained for which they are intended : the powder thus produced is preserved, and used for polishing them in a kind of mill furnished with a wheel of iron ; the diamond is then secured in a brazen dish, and the dust mixed with olive oil applied, the wheel is set in motion, and the friction occasions the polished surface so necessary to give their lustre due effect. Other stones, as rubies, topazes, and sapphires, are cut into various angles on a wheel of copper, and the material for polishing those is tripoli diluted with water. A leaden wheel, covered with emery mixed with water, is preferred for the cutting of emeralds, amethysts, hyacinths, agates, granites, &c. &c. and they are polished on a pewter wheel with tripoli; opal, lapis lazuli, &c. are polished on a wheel made of wood. Contrary to the method used by persons who turn metals, in which the substance to be wrought is fixed in the lathe, turned by it, and the tool held to the substance, the engraver of the crystal, lapis lazuli, &c. fixes his tools in the lathe, and holds the precious stone to them, thus forming vases, or any other shape, o interposing diamond dust mixed with oil, or emery and water, between the tool and the substance, as often as it is dispersed by the rotary motion of the forInler. The engraving of armorial bearings, single figures, devices, &c. on any of the above stones, after they are polished, is performed through the means of a small iron wheel, the ends of the axis of which are received within two pieces of iron, in a perpendicular position, that may be closed, or otherwise, as the operation requires; the tools are fixed to one end of the axis, and screwed firm ; the stone to be engraved is then held to the tool, the wheel set in motion by the foot, and the figure gradually formed. The materials of which the tools are made is generally iron, and sometimes brass; they are flat, like chissels, gouges, ferules, and others have circular heads. After the work is finished, the polishing is done with hair brushes, fixed on wheels and tripoli. Engraving in wood, has been practised for several centuries, and originally with tolerable success; it languished for great part of the 18th century, but revived towards the close, and is still practised in a manner which reflects credit on the ingenuity of the age. Bewick will long be remembered by his works in this style of engraving, and his imitators have been numerous and successful. As it is entirely different from engraving on copper, the artist already acquainted with that mode would find himself at a loss how to proceed on wood, as the lines, instead of being cut into the substance, are raised, like the letters of printing types, and printed in the same manner. The wood used for this purpose is box, which is preferred for the hardness and closeness of its texture; the surface must be planed smooth, and the design drawn on it with a black lead pencil; the graver is then used, the finer excavations from which are intended for white interstices between the black lines produced by leaving the box untouched, and the greatest lights are made by cutting away the wood entirely, of the intended form, length and breadth; but the deepest shades require no engraving. Much of the beauty of this kind of engraving depends upon the printing, nor
is it every artist who can excel in it, as expedition and freedom are not to be attained : in short, the best wooden cuts are evidently the products rather of perseverance and ingenuity than easy confidence in ability, observable in every line of fine etchings. There are some who succeed to admiration in representing foliage and plants, but unfortunately a few months practice will enable a pupil to etch them on copper with greater truth : drapery and architecture may be well done in wood, but the faces and limbs of figures never iock well. Such are the different descriptions of engraving which do not require the aid of aqua fortis; of those made by the intervention of that liquid, the principal is Etching. He that would excel in this branch of the arts must be thoroughly acquainted with drawing; otherwise his works will appear tasteless indeed. The ground used in etching is a combination of asphaltum, gum mastic, and virgin wax, mixed in such proportions as will prevent the asphaltum from breaking the composition, when under the aqua fortis or the wax from making it so soft as to close the lines when cut through it by the needle. As every thing depends upon the stability of the ground, it should be purchased of those persons who are most celebrated for making it; or if the person wishing to use it prefers doing it himself, let him remember, that he must keep every particle of grease or oil far from him and his materials, and that, without the greatest care, the inflammability of the asphaltum will ruin his operations in melting them. The proportions of the ingredients should be obtained by experiment. After being prepared in the above manner, the ground is tied in a piece of lustring for use, and another piece of the same kind of silk must be made into a dabber by tying a quantity of cotton in it. The copper-plate, hammered to a considerable degree of hardness, polished as if intended for the graver, and perfectly cleansed with whiting, is then secured at one corner by a hand vice, heated over a charcoal fire, and the silk containing the ground rubbed over it, till every part is covered by the melted composition ; but before it cools the silk dabber must be applied in all directions, till the surface of the plate is thinly and cqually varnished. After this part of the process is completed, several lengths of wax taper, twisted together, are to be lighted, the plate raised by the vice in the left hand, and the right, hoiding the burning taper, is to be moved gently backwards and forwards under the ground, carefully avoiding touching it with the wick, yet causing the flame to spread over the surface, which will render it perfectly black, sunooth, and shining, in a short time ; this is to be ascertained by turning the plate: If the copper appears through the ground, the taper must be applied again immediately ; but if it is held too long beneath the plate, the ground will become opaque, and break when the aqua fortis is used. The next object is, to transfer the design to the ground, which may be done by drawing it on thin white paper with a black-lead pencil, and having it passed through the copper-plate printer's rolling press, who will accomplish it by laying the plate carefully on the board of his press, the pencilled paper slightly damped on it, and turning the press, the lead will be conveyed fi mly to the ground, which will appear in perfect outlines on removing the paper. Another method is, to draw the design reversed from the original; rub the back with powdered white chalk, and laying it on the ground, trace the lines through with a blunt point: this operation requires much precaution, or the point will cut the ground; besides, if the paper is not securely fastened with wax at the corners, it may slip, and either interrupt the true continuation of the lines, or scratch the ground. In working with the etching needle nothing more is required than to keep it upright, that the lines made by it through the ground may not slope, and thus make the aqua fortis corrode improperly ; but it should be particularly observed, that the point, though taper, must be so rounded as to be free from a possibility of its tearing the surface of the copper, which would prevent the progress of the point, and ruin the plate when bitten ; the necessary polish of the point may be accomplished by rubbing it on the sole of a shoe. The young artist must now be left to his own exertions, as directions for etching beyond those already given are useless, and he will acquire more knowledge and freedom from copying good prints in one week than a quarto volume of observations would afford. It seems almost needless to add, that every line must be kept distinct, at all events, throughout the plate, and that the most distant should be closer and more regular than those in the fore ground, as the
greater the depth of shade the broader and deeper must the lines be made. When the etching of the plate is completely finished, the edges of it must be surrounded by a high border of wax, so well secured that water will not penetrate between the plate and it. The best spirits of nitre fortis must then be diluted with water, in the proportion of one part of the former to four of the latter, which will be found to answer the first operations, if the weather is fine and the atmosphere free from moisture ; but if the contrary is the case, the spirits of nitre must be increased in proportion to the humidity of the air; this, when poured on the plate, cannot be too attentively observed, in order to remove the bubbles of fixed air with a feather, and to ascertain the time for stopping out the lightest parts; for it must be remembered, the whole secret of biting or corroding any subject consists in the judicious manner in which the depth and breadth of the lines are varied, as by proper management they may be left scarcely perceptible, or increased very considerably. The composition used for the above purpose is turpentine varnish mixed with lampblack, and diluted so as to be used freely with a camel's hair pencil; this, applied to the parts of the plate sufficiently corroded, will effectually prevent the aqua fortis from touching it again, and the remainder proceeds as if no such application had taken place : it will be necessary to strengthen the water as the work be. comes nearer completion, but cautiously, lest the ground should be broken ; and every time the aqua fortis is removed, the plate must be washed with clean water, and gradually dried, otherwise the varnish cannot be used, and the lines would be clogged with the decomposed metal. For taking the ground from the plate it is usual to cover the surface with olive oil, and heating it, wipe the plate with a soft piece of old linen and spirits of turpentine, will effectually remove all remaining dirt, Re-biting, is the art of strengthening those lines of an etching, in a plate from which the original ground has been cleans. ed. This is done by applying the ground as at first directed, but with great care, that the melted composition does not fill, or even partially fill the lines, to prevent which the cotton wrapt in silk, called the dubber, should be used exclusively, by taking a small quantity of melted ground on it, and gently touching the parts between the lines, till they are equally and completely covered; if the plate is considerably heated, the ground will spread with more facility over the various interrupted surfaces. Carelessness or inattention will instantly ruin this process, and the whole of the plate: a border of wax must surround the parts to be re-bitten, and a channel made to carry off the aqua fortis without injuring those already completed. Supposing the operations of etching and biting the plate entirely finished, nothing more remains than to examine it attentively, and improve it with the graver and dry point. Stipling, or engraving in the dotted manner, was in a great measure introduced by Bartolozzi, whose works in this way are astonishingly numerous, exclusive of those to which his name is affixed, and not the products of himself. Some pastoral scenes, with figures, when printed in colours, have a pleasing effect; and small portraits stipled will bear examination ; but historical subjects, which have great breadth of shade, appear to no advantage engraved in this manner. Stipling is performed by etching the plate with dots, and biting it, laying the shades with a tool for the purpose, using the graver and the dry point, and scraping off the roughness thus occasioned. Engraving in .1quatinta. The print from an aquatinted plate resembles a neatly finished drawing in Indian ink; this effect is produced by corroding the plate between the particles of a material entirely different from the etching ground. The first step in this process is, to prepare a plate exactly in the way already described, and etch the outlines of the subject to be aquatinted, which are to be slightly bitten, and the plate thoroughly cleansed. The substance used to form the grains of the subject (which may be common resin, burgundy-pitch, asphaltum, gum-mastich, or gum-copal, either separate or mixed) should be reduced to a fine powder and sifted, put into a piece of muslin, and holding it high above the plate, it must be struck against any substance held in the left hand, till the shower of dust thus produced has covered the plate equally throughout; preserving it carefully in this situation, the plate is to be heated sufficiently to melt the powder, which will make the grains assume a circular form, and contract, leaving, when cold, a beautiful surface fit for the aqua fortis. Common resin is generally preferred for this part of the operation, but gum-copal is less lia
ble to be broken loose from the plate during the process of biting. The drawing to be copied must serve as the future basis of proceeding, which is to be imitated in the following manner: the perfectly white parts of the intended print are to be covered on the plate with the varnish mentioned in etching, by the use of a camel's-hair pencil, a border of wax must then be raised, and the aqua fortis, diluted, poured on ; the same method is afterwards practised in the stopping out before recommended, except that the depth of the corroding cannot be so great as in the line manner. In order to obviate any difficulties which occur in procuring sufficient depths of shade, a method has been invented, that enables the artist to produce an ef. fect almost equal to the decisive touches of a brush filled with colour in drawing, which is the use of a liquid made with water, treacle, or sugar, and fine washed whiting, exactly of the consistence of Indian ink, and laid on the granulated surface with a pencil, in the same free manner No. paper; after the above composition is thoroughly dry, the whole plate must be covered with a thin, weak, varnish of mastich, turpentine, or asphaltum, and, when dried a second time, the aqua fortis is to be applied, which immediately breaking the varnish and whiting, will corrode the plate precisely in the marks of the pencil. The border of wax may be removed by o, the plate gently, and the ground varnish, &c. by oil of turpentine ; a little fine whiting and a clean rag will then render the plate fit for the printer. As the manner of procuring the grain by heating the powdered substance scattered over the plate is liable to objections, on account of the difficulty of making the particles assume the desired coarseness, or the reverse, and the chgraving so produced rapidly wearing out in the printing, another has been contrived, far more certain and satisfactory. In this mode, common resin, mastich, or Burgundy pitch, is dissolved in highly rectified spirits of wine of the best quality, each of which produces different descriptions of grains; but these sub stances may be mixed in such proportions as the artist prefers, and he must recollect that the resin makes the coarsest; to satisfy himself in this prrticular, the grain of every proportion should be tried on useless pieces of copper. Having a solution to his mind, it must remain undisturbed till every impure particle has