Vasari on technique

What Sculpture is; how good works of Sculpture are made, and what qualities they must possess to be esteemed perfect.

§ 36. The Nature of Sculpture.

Sculpture is an art which by removing all that is superfluous from the material under treatment reduces it to that form designed in the artist’s mind.^[152]

§ 37. Qualities necessary for Work in the Round.

Now seeing that all figures of whatever sort, whether carved in marble, cast in bronze, or wrought in plaster or wood, must be in salient work in the round, and seeing too that as we walk round them they are looked at from every side, it is clear that if we want to call them perfect they must have many qualities. The most obvious is that when such a figure is presented to our eyes, it should show at the first glance the expression intended, whether pride or humility, caprice, gaiety or melancholy—according to the personage portrayed. It must also be balanced in all its members: that is, it must not have long legs, a thick head, and short and deformed arms; but be well proportioned, and from head to foot have each part conforming with the others. In the same way, if the figure have the face of an old man, let it have the arms, body, legs, hands, and feet of an old man, the skeleton symmetrically ordered throughout, the muscles and sinews and veins all in their proper places. If it have the face of a youth, it must in like manner be round, soft and sweet in expression, harmonious in every part. If it is not to be nude, do not let the drapery that is to cover it be so meagre as to look thin, nor clumsy like lumps of stone, but let the flow of the folds be so turned that they reveal the nude beneath—and with art and grace now show now hide it without any harshness that may detract from the figure. Let the hair and beard be worked with a certain delicacy, arranged and curled to show they have been combed, having the greatest softness and grace given to them that the chisel can convey; and because the sculptors cannot in this part actually counterfeit nature, they make the locks of hair solid and curled, working from manner^[153] rather than in imitation of nature. Even though the figures be draped, the feet and hands must be modelled with the care and beauty shown in the other parts. And as the figure is in the round, it is essential that in front, in profile, and at the back, it be of equal proportions, having at every turn and view to show itself happily disposed throughout. Indeed the whole work must be harmonious, and exhibit pose, drawing and unity, grace and finish; these qualities taken together show the natural talent and capacity of the artist.

§ 38. Works of Sculpture should be treated with a view to their destined position.

Figures in relief as well as in painting ought to be produced with judgement rather than in a mechanical way,^[154] especially when they are to be placed on a height, at a great distance. In this position the finish of the last touches is lost, though the beautiful form of the arms and legs, and the good taste displayed in the cast of drapery, with folds not too numerous, may easily be recognized; in this simplicity and reserve is shown the refinement of the talent. Figures whether of marble or of bronze that stand somewhat high, must be boldly undercut in order that the marble which is white and the bronze which tends towards black may receive some shading from the atmosphere, and thus the work at a distance appear to be finished, though from near it is seen to be left only in the rough. This was a point to which the ancients paid great attention, as we see in their figures in the round and in half relief, in the arches and the columns in Rome, which still testify to the great judgement they possessed. Among the moderns, the same quality is notably exhibited in his works by Donatello. Again, it is to be remembered, that when statues are to be in a high position, and there is not much space below to enable one to go far enough off to view them at a distance, but one is forced to stand almost under them, they must be made one head or two taller. This is done because those figures which are placed high up lose in the foreshortening, when viewed by one standing beneath and looking upwards. Therefore that which is added in height comes to be consumed in the foreshortening, and they turn out when looked at to be really in proportion, correct and not dwarfed, nay rather full of grace. And if the artist should not desire to do this he can keep the members of the figure rather slender and refined, this gives almost the same effect.

§ 39. The Proportions of the Human Figure.

It is the custom of many artists to make the figure nine heads high; dividing it in the following manner; the throat, the neck, and the height of the foot (from the instep to the sole) are equal to one head and the rest of the body to eight; of these, the shinbone measures two heads, from the knee to the organs of generation two more, while the body up to the pit of the throat is equal to three, with another from the chin to the top of the forehead, so that there are nine in all.^[155] As to the measurements across, from the pit of the throat to the shoulder on each side is the length of a head, and each arm to the wrist is three heads. Thus the man with his arms stretched out measures exactly as much as his height.

§ 40. Artists must depend on their Judgement rather than on the Measuring Rule.

After all the eye must give the final judgement, for, even though an object be most carefully measured, if the eye remain offended it will not cease on that account to censure it.

Let me repeat that although measurement exercises a just control in enlarging the figure so that the height and breadth, kept according to rule, may make the work well proportioned and beautiful, the eye nevertheless must decide where to take away and where to add as it sees defect in the work, till the due proportion, grace, design and perfection are attained, so that the work may be praised in all its parts by every competent authority. And that statue or figure which shall have these qualities will be perfect in beauty, in design and in grace. Such figures we call figures ‘in the round,’ provided that all the parts appear finished, just as one sees them in a man, when walking round him; the same holds good of all the details which depend on the whole. But it seems to me high time to come to the particulars of the subject.

Of the manner of making Models in Wax and in Clay; how they are draped, and how they are afterwards enlarged in proportion in the Marble; how Marbles are worked with the point and the toothed tool, and are rubbed with pumice stone and polished till they are perfect.

§ 41. The small Sketch-Model in Wax or Clay.

Sculptors, when they wish to work a figure in marble, are accustomed to make what is called a model for it in clay or wax or plaster; that is, a pattern, about a foot high, more or less, according as is found convenient, because they can exhibit in it the attitude and proportion of the figure that they wish to make, endeavouring to adapt themselves to the height and breadth of the stone quarried for their statue.

§ 42. The Preparation of Wax.

In order to show how wax is modelled, let us first speak of the working of wax and not of clay. To render it softer a little animal fat and turpentine and black pitch are put into the wax, and of these ingredients it is the fat that makes it more supple; the turpentine adds tenacity, and the pitch gives it the black colour and a certain consistency, so that after it has been worked and left to stand it becomes hard. And he who would wish to make wax of another colour, may easily do so by putting into it red earth, or vermilion or red lead; he will thus make it of a yellowish red or some such shade; if he add verdigris, green, and so on with the other colours. But it is well to notice that the colours should be ground into powder and sifted, and in this state afterwards mixed with the wax made as liquid as possible. The wax is also made white for small things, medals, portraits, minute scenes and other objects of bas-relief. And this is done by mixing powdered white lead with the white wax as explained above.

§ 43. Polychrome Wax Effigies.^[156]

Nor shall I conceal that modern artists have discovered the method of working in wax of all sorts of colours, so that in taking portraits from the life in half relief, they make the flesh tints, the hair, the clothes and all the other details so life-like that to these figures there lacks nothing, as it were, but the spirit and the power of speech.

§ 44. The Manipulation of Wax over an Armature.

But to return to the manner of preparing the wax; when the mixture has been melted and allowed to go cold, it is made into sticks or rolls. These from the warmth of the hands become, in the working, like dough and are suitable for modelling a figure that is seated or erect or as you please. To make the figure support itself, it may have underneath the wax an armature either of wood, or of iron wires according to the pleasure of the artist; or this can be omitted if it suit him better. Little by little, always adding material, with judgement and manipulation, the artist impresses the wax by means of tools made of bone, iron, or wood, and again putting on more he alters and refines till with the fingers the utmost finish is given to the model.

§ 45. The Small Model in Clay.

Should he wish to make his model in clay, he works exactly as with wax, but without the armature of wood or iron underneath, because that would cause the clay to crack open or break up;^[157] and that it may not crack while it is being worked he keeps it covered with a wet cloth till it is completed.

§ 46. The Full-sized Model in Clay.

When these small models or figures of wax or clay are finished, the artist sets himself to make another model as large as the actual figure intended to be executed in marble. In fashioning this he must use deliberation, because the clay which is worked in a damp state shrinks in drying; he therefore, as he works, adds more bit by bit and at the very last mixes some baked flour with the clay to keep it soft and remove the dryness.^[158] This trouble is taken that the model shall not shrink but remain accurate and similar to the figure to be carved in marble. To ensure that the large clay model shall support itself and the clay not crack, the artist must take some soft cuttings of cloth or some horse hair, and mix this with the clay to render it tenacious and not liable to split. The figure is supported by wood underneath with pressed tow or hay fastened to it with string.^[159] The bones of the figure are made and placed in the necessary pose after the pattern of the small model, whether erect or seated; and from the beginning to the end of the process of covering it with clay the figure is formed in the nude.

§ 47. Drapery on the Clay Model.

This completed, if the artist desire afterwards to clothe it with thin drapery, he takes fine cloth, if with heavy, he takes coarse, and wets it and then covers it over with clay, not liquid but of the consistency of rather thick mud, and arranges it around the figure in such folds and creases as the mind suggests; this when dry, becomes hardened and continues to keep the folds.^[160]

§ 48. Transference of the Full-sized Model to the Marble Block.

Models, whether of wax or of clay, are formed in the same manner. To enlarge the figure proportionately in the marble^[161] it is necessary that against this same block, whence the figure has to be carved, there shall be placed a carpenter’s square, one leg of which shall be horizontal at the foot of the figure while the other is vertical and is always at right angles with the horizontal, and so too with the straight piece above; and similarly let another square of wood or other material be adjusted to the model, by means of which the measures may be taken from the model, for instance how much the legs project forward and how much the arms. Let the artist proceed to carve out the figure from these measurements, transferring them to the marble from the model, so that measuring the marble and the model in proportion he gradually chisels away the stone till the figure thus measured time after time, issues forth from the marble, in the same manner that one would lift a wax figure out of a pail of water, evenly and in a horizontal position. First would appear the body, the head, and the knees, the figure gradually revealing itself as it is raised upwards, till there would come to view the relief more than half completed and finally the roundness of the whole.

§ 49. Danger of dispensing with the Full-sized Model.

Those artificers who are in a hurry to get on, and who hew into the stone at the first and rashly cut away the marble in front and at the back have no means afterwards of drawing back in case of need.^[162] Many errors in statues spring from this impatience of the artist to see the round figure out of the block at once, so that often an error is revealed that can only be remedied by joining on pieces, as we have seen to be the habit of many modern artists. This patching is after the fashion of cobblers and not of competent men or rare masters, and is ugly and despicable and worthy of the greatest blame.

§ 50. The Tools and Materials used in Marble Carving.

Sculptors are accustomed, in working their marble statues, to begin by roughing out the figures with a kind of tool they call ‘subbia,’ which is pointed and heavy; it is used to block out their stone in the large, and then with other tools called ‘calcagnuoli’ which have a notch in the middle and are short, they proceed to round it, till they come to use a flat tool more slender than the calcagnuolo, which has two notches and is called ‘gradina’: with this they go all over the figure, gently chiselling it to keep the proportion of the muscles and the folds, and treating it in such a manner that the notches or teeth of the tool give the stone a wonderful grace. This done, they remove the tooth marks with a smooth chisel, and in order to perfect the figure, wishing to add sweetness, softness and finish to it, they work off with curved files all traces of the gradina. They proceed in the same way with slender files and straight rasps, to complete the smoothing process,^[163] and lastly with points of pumice stone they rub all over the figure to give that flesh-like appearance that is seen in marvellous works of sculpture. Tripoli earth is also used to make it lustrous and polished, and for the same reason it is rubbed over with straw made into bunches—till, finished and shining, it appears before us in its beauty.^[164]

Of Low and Half Reliefs, the difficulty of making them and how to bring them to perfection.

§ 51. The Origin of Reliefs.

Those works that sculptors call half reliefs^[165] were invented by the ancients to make figure compositions with which to adorn flat walls, and they adopted this treatment in theatres and triumphal arches, because, even had they wished to sculpture figures in the round, they could not place them unless they first constructed a standing ground or an open place that was flat. Desiring therefore to avoid this, they invented a kind of sculpture which they named half relief, and it is called ‘mezzo rilievo’ still among ourselves.

§ 52. Pictorial or Perspective Reliefs.

In the manner of a picture this kind of relief sets forth first the whole of the principal figures, either in half round or still greater salience, as may happen, the figures on the second plane partly hidden by the first, and those on the third by the second, just as living people are seen when they are assembled and crowded together. In this kind of half relief, for the sake of perspective, they make the most distant figures low, some of the heads indeed extremely low, and no less so the houses and scenery which are the objects most remote. By none has this species of half relief ever been better executed, with more observation, or with its figures diminished and spaced one from the other more correctly than by the ancients;^[166] for they, who were students of the truth and gifted artists, never made the figures in such compositions with ground that is foreshortened or seems to run away, but placed them with their feet resting on the moulding beneath them. In contrast to this, some of our own moderns, over eager, have, in their compositions in half relief, made their principal figures stand on the plane which is in low relief and recedes, and the middle figures on the same plane in such a position that, as they stand, they do not rest the feet as firmly as is natural, whence it not infrequently happens that the points of the feet of those figures that turn their backs actually touch the shins of their own legs, so violent is the foreshortening. Such things are seen in many modern works, and even in the gates of the Baptistry and in many examples of that period. Therefore half reliefs of this character are incorrect, because, if the foremost figures project half out of the stone while others have to be placed behind them, there must be a rule for the retiring and diminution; the feet of the figures have to be on the ground, so that the ground may come forward in front as required by the eye and the rule in things painted. Accordingly the figures must be gradually reduced in proportion as they recede till they reach the flattened and low relief; and because of the harmony required it is difficult to carry out the work perfectly seeing that in relief the feet and heads are foreshortened. Great skill in design therefore is necessary if the artist wish to exhibit his ability in this art. The same degree of perfection is demanded for figures in clay or wax as for those worked in bronze and marble. Therefore of all the works which have the qualities that I indicate the half reliefs may be considered most beautiful and most highly praised by experienced artists.

The second species called low reliefs projects much less than the half reliefs; they have not more than half the boldness of the others, and one can rightly make in these low reliefs the ground, the buildings, the prospects, the stairs and the landscapes as we see in the bronze pulpits in San Lorenzo at Florence, and in all the low reliefs of Donatello, who in this art produced things truly divine with the greatest truth to nature. These reliefs present themselves easily to the eye and without errors or barbarisms, seeing that they do not project forward so much as to give occasion for errors or censure.

§ 54. Flat Reliefs (Stiacciati Rilievi).

The third species called low or flattened reliefs only shows up the design of the figure in the very lowest and most depressed relief. These reliefs are very difficult for they demand great skill in design and invention, and as all depends on the outlines it is a hard thing to impart charm to them. Donatello worked better here than did any other, with art, design and invention.^[167] In the ancient vases of Arezzo,^[168] many figures, masks, and other ancient compositions are to be seen in this sort of work: likewise in the antique cameos, in moulds for striking bronze pieces for medals, and also in coins. This style was chosen because, if the relief had been too high, the coins could not have been struck, for the blow of the hammer would not have produced the impression since the punches have to be pressed on to the cast material, and when this is in low relief it costs little trouble to fill the cavities of the punch. Now-a-days we see that many modern artists have worked divinely in this style, more even than did the ancients, as shall be fully described in their Lives. Therefore, he who recognizes in the half reliefs the perfection of the figures so carefully made to diminish, and in the lower reliefs the excellence of the design in the perspectives and other inventions, and in the flattened reliefs the clearness, the refinement and the beautiful form of the figures, will do well to regard them on account of these qualities as worthy of praise or blame, and will teach others also so to regard them.

How Models for large and small Bronze Figures are made, with the Moulds for casting them and their Armatures of iron; and how they are cast in metal and in three sorts of Bronze; and how after they are cast they are chased and refined; and how, if they lack pieces that did not come out in the cast, these are grafted and joined in the same bronze.

§ 55. The Full-sized Model for Bronze.

It is the custom of competent artists, when they wish to cast large figures in metal or bronze,^[169] to make first a statue of clay as large as that intended to be cast in metal, and to perfect the clay statue as far as their art and their knowledge will allow.

§ 56. The Piece-Mould in Plaster.

When this, which they call the model, is finished and brought to this point of perfection, they then begin, with plaster that will set, to build over it piece by piece, making the pieces correspond to the relief of the model. On every piece they make a key, marking the pieces with numbers or letters of the alphabet or with other signs in order that the pieces can be taken off and register together. So they mould it part by part, oiling the pieces of the cast where the edges have to be connected; till from piece to piece the figure grows, the head, the arms, the body and the legs, to the last detail, in such a manner that the concave of the statue, that is the hollow mould, comes to be imprinted on the inner surface with all the parts and with the very minutest marking which is in the model.^[170] This completed, the plaster casts are laid aside to harden.

§ 57. The Construction of the Core.

The workers then take a rod of iron longer than the whole figure that they wish to make, and that is to be cast, and over this they make a core of clay into which, while kneading it to make it soft, they mix horse dung and hair. The core has the same form as the model and is baked in successive layers so as to draw out the dampness of the clay; this is of use afterwards to the figure, for in casting the statue all this core, which is solid, leaves an empty space that is not filled with bronze, because if it were, the figure could not be moved on account of the weight. They make this core large enough and justly measured, so that when the layers are heated and baked, as has been said, the clay becomes well burned through and so entirely freed from damp, that in pouring the bronze upon it afterwards it does not spurt nor do injury, as has happened many times, involving the death of the masters and the ruin of the work. Thus they go on balancing the core and adjusting and examining the pieces, till they tally with it and represent it, so that there comes to be left exactly the thickness, or, (if we like to say so,) the thinness, of the metal, according as you wish the statue to be.

Frequently this core has an armature of rods of copper across it, and irons that can be taken out and put in to hold it with security and with greater strength.^[171] The core, after it is finished, is yet again baked with a gentle heat, and the moisture, should any have remained, entirely removed; it is then again laid aside.

§ 58. The Piece-Mould lined with a Skin of Wax.

Returning now to the pieces of the hollow mould, these are lined severally with yellow wax that has been softened and incorporated with a little turpentine and tallow.^[172] When the wax is melted at the fire, it is poured into the two halves of the mould made up of the hollow pieces in such a manner as causes the wax to come thin according to the worker’s idea for the cast, and the pieces, which have been shaped to correspond with the relief of the core already made of clay, are joined to it and fitted and grafted together.

§ 59. This Skin of Wax applied over the Core.

With thin skewers of copper the pieces of wax pierced with the said skewers are now fixed to the baked core, and so, piece by piece, they are inserted and fitted to the figure and render it entirely finished. This completed they proceed to remove all the superfluous wax that has overflowed into the interstices of the pieces, and bring it as well as possible to that finished excellence and perfection which one desires in the bronze cast. Before going further, the craftsman sets up the figure and considers diligently if the wax have any deficiency, and he proceeds to repair it and to fill up again, putting on more or taking away where necessary.^[173]

§ 60. The fire-resisting Envelope applied over the Wax.

After that, the wax being completed and the figure braced together, he puts it where fire can be applied to it^[174] on two andirons of wood, stone, or iron like a roast, arranging so that it can be raised or lowered; and with moistened ash, specially fitted for that purpose, by means of a paint brush he covers the entire figure so that the wax is quite concealed, and over every hollow and chink he clothes it well with this material. Having applied the ash to it he replaces the transverse rods, which pass through the wax and the core, just as he has left them in the figure, because these have to support the core within and the mould without, which is the casing of the hollow space between the core and the mould, where the bronze is to be poured. When this armature has been fixed, the artificer begins to take some fine earth, beaten together with horse dung and hair, as I said, and carefully lays a very thin coating all over which he allows to dry, and so on time after time with other coatings, always allowing each to dry until the figure becomes covered with earth raised to the thickness of half a span at the most.

§ 61. The External Armature.

This done, he girds those irons that hold the core within with other irons which hold the mould outside, and fixes them together, so that chained and bound the one to the other they form a mutual support,^[175] the core within sustaining the mould without and the mould without holding firm the core within.

§ 62. The Vents.

It is usual to make certain little pipes between the core and the outer mould called vents, that have issue upwards; they are put, for instance, from a knee to an arm that is raised, because these give passage to the metal^[176] to make up for that which on account of some impediment may not flow properly, and these little tubes are made many or few, according as the casting is difficult or not.

§ 63. The Wax melted out.

This done, the worker proceeds to apply heat to the said mould equally all over, so that it may become united and little by little be warmed through, and he increases the heat till the mould is thoroughly hot throughout, so that the wax which is in the hollow space becomes melted and all flows out at the spot through which the metal is to be poured, without any particle of the wax remaining within.^[177] To be sure of this, it is needful, before the pieces of wax are grafted in to their places on the figure, to weigh them piece by piece; in the same way after drawing out the wax, it must be weighed again, when by making the subtraction the artist sees if any wax be left between the core and the mould, and how much has come out. Notice that the skill and care of the artist is manifested in the process of taking out the wax; herein is seen the difficulty of producing the casts so that they come out sharp and beautiful, for if any of the wax be left, it would ruin the whole cast, especially that part where the wax remains.

§ 64. The Mould in the Casting-pit.

This finished, the craftsman puts the mould under ground near to the furnace where the bronze is melted, propping it so that the bronze may not strain it, and he makes the channels through which the bronze is to flow, and at the top he leaves a certain thickness, which allows for the surplus of the bronze to be sawn off afterwards, and this he does in order to secure sharpness.^[178]

§ 65. The Composition of the Bronze.

The artist prepares the metal as he thinks fit, and for every pound of wax he puts ten pounds of metal.^[179] Statuary metal is made of the combination of two thirds of copper and one third of brass according to the Italian rule. The Egyptians, from whom this art took its origin, put into the bronze two thirds of brass and one third of copper. In electron metal, which is the finest of all, two parts copper are put to one part silver. In bells, for every hundred parts of copper there are twenty of tin, in order that the sound of the bells may carry far and be more blended; and for artillery, in every hundred parts of copper, ten of tin.^[180]

§ 66. Making up Imperfections.

There only remains to us now to teach the method of grafting a piece into the figure should it have a defect, either because the bronze coagulated, or ran too thin, or did not reach some part of the mould. In this case let the artificer entirely remove the defective part of the cast and make a square hole in its place, cutting it out under the carpenter’s square, then let him adjust a piece of metal prepared for that spot, that may project upward as much as he pleases, and when fitted exactly in the square hole let him strike it with the hammer to send it home, and with files and tools make it even and thoroughly finished.

Now should the artificer wish to cast small figures in metal, they are first made of wax, or if he happen to have them in clay or other material, he makes the shell of plaster over them in the same way as for the large figures, and fills it all with wax. But the shell must be moistened that the wax, when poured into it, may set (with a hard skin) by reason of the coldness of the wet cast. Then by shaking about and agitating the cast, the wax (which is not hardened) within the cavity is thrown out, so that the cast remains hollow in the interior: the craftsman afterwards fills up the vacant space with clay and puts in skewers of iron. This clay serves then for core, but it must be allowed to dry well. Thereafter he adjusts the mould as for the other large figures, giving it its armature and placing the tubes for the vents. Then he bakes it and gets rid of the (skin of) wax and thus the vacant space remains clear so that the bronze can easily be poured in. The same is done with the low and half reliefs and with every other work in metal.

§ 68. Chasing the Cast and Colouring the Bronze.

These casts being finished, the workman then, with suitable tools, that is, with burins, burnishers, chasing tools, punches, chisels and files, removes material where needed, and where needed presses inward the overflow of the metal and smoothes it down; and with other tools that scrape, he shaves and cleans the whole of it diligently, and finally with pumice stone gives the last polish. This bronze which is red when it is worked assumes through time by a natural change a colour that draws towards black. Some turn it black with oil, others with vinegar make it green, and others with varnish give it the colour of black, so that every one makes it come as he likes best.

§ 69. Modern Tours de Force in small Castings.

But that is a truly marvellous thing which is come to pass in our times, this mode of casting figures, large as well as small, so excellently that many masters make them come out in the cast quite clear so that they have not to be chased with tools, and as thin as the back of a knife. And what is more, some clays and ashes used for this purpose are actually so fine, that tufts of rue and any other slender herb or flower can be cast in silver and in gold, quite easily and with such success, that they are as beautiful as the natural; from which it is seen that this art is more excellent now than it was in the time of the ancients.

Concerning Steel Dies for making Medals of bronze or other metals and how the latter are formed from these metals and from Oriental Stones and Cameos.

§ 70. The Fabrication of Matrices for Medals.

The craftsman who wishes to make medals of bronze or silver or gold after the manner of the ancients, must first with iron punches work in relief the faces of steel dies of which the metal has been softened piece by piece in the fire; as for example, the head alone in low relief, in a single steel die; and so with the other parts which are joined to it. Fashioned thus of steel, all the dies needed for the medal are tempered by fire; and on the block of tempered steel, that is to serve for mould and matrix of the medal, the artist proceeds to imprint by means of hammer strokes the head and the other parts in their proper places. And after imprinting the whole, he diligently smoothes it and polishes it again, giving finish and perfection to the said mould that has afterwards to serve for matrix. Many artificers have been in the habit however of carving the matrices with wheels, just as intaglio work is done in crystals, jaspers, calcedonies, agates, amethysts, sardonyx, lapis lazuli, chrysolites, cornelians, cameos and other oriental stones; and the work done in this way makes the matrices more sharp, as is the case in the aforesaid stones. In the same way they make (the matrix for) the reverse of the medal, and with these two, the matrix of the head and that of the reverse side, (trial) medals of wax and of lead are struck. These are moulded afterwards with a very finely powdered earth suitable for the purpose; and in these moulds, when the wax or leaden (trial) medal has been taken out, and they are pressed together in the frame, you may cast any kind of metal which pleases you for your medal.

These casts are then replaced in the steel matrices that correspond to them and by force of screws or wedges and with hammer blows they are pressed so tightly, that they take that finish of surface from the stamp that they have not taken from the casting process. But coins and other medals in low relief are stamped without screws, by blows of the hammer struck by hand.^[181]

§ 71. The Cutting of Intaglios and Cameos.

Those oriental stones that we spoke of above are cut in intaglio with wheels by means of emery, which with the wheel cuts its way through any sort of hardness of any stone whatever. And as the craftsman proceeds, he is always testing by wax impressions the intaglio which he is fashioning; and in this manner he goes on removing material where he deems it necessary, till the final touches are given to the work. Cameos however are worked in relief; and because this stone is in layers, that is white above and dark underneath, the worker removes just so much of the white as will leave the head or figure white on a dark ground. And sometimes, in order to secure that the whole head or figure should appear white on a dark ground, he dyes the ground when it is not so dark as it should be. In this art we have seen wondrous and divine works both ancient and modern.

How works in White Stucco are executed, and of the manner of preparing the Wall underneath for them, and how the work is carried out.

§ 72. Modelled and stamped Plaster Work.

The ancients, when they wished to make vaults or panels or doors or windows or other ornaments of white stucco, were in the habit of building a skeleton of walling either of baked bricks or of tufa, that is, a stone that is soft and easy to cut. Making use of these, they built up the bones underneath, giving them the form of mouldings or figures or whatever they wished to make, cutting them out of the bricks or stones, which were afterwards put together with mortar.

Then with stucco, which in our fourth chapter (of Architecture) we described as crushed marble mixed with lime from travertine, they begin to cover the aforesaid skeleton with the first daub of rough stucco, that is coarse and granulated, to be covered over with finer when the first stucco has set and is firm, but not thoroughly dry. The reason for this is that to work the mass of the material above a damp bed makes it unite better, therefore they keep wetting the stucco at the place where the upper coating is laid on so as to render it more easy to work.

To make (enriched) mouldings or modelled leafage it is necessary to have shapes of wood carved in intaglio with those same forms that you wish to render in relief. The worker takes stucco that is not actually hard nor really soft, but in a way tenacious, and puts it on the work in the quantity needed for the detail intended to be formed. He then places over it the said hollowed mould which is powdered with marble dust, striking it with a hammer so that the blows fall equally, and this leaves the stucco imprinted; he then proceeds to clean and finish it so that the work becomes true and even. But if he desire the work to have bolder relief in projection, in the spot where this is to come he fixes iron supports or nails or other armatures of a similar kind which hold the stucco suspended in the air, and by these means the stucco sets firmly, as one sees in the ancient edifices where the stucco and the iron supports are found still preserved to the present day.^[182] Moreover, when the artificer wishes to produce a composition in bas-relief on a flat wall, he first inserts numerous nails in the wall, here projecting less, there more, according as the figures are to be arranged, and between these he crowds in little bits of brick or tufa, in order that the ends or heads of these may hold the coarse stucco of the first rough cast, which he afterwards goes on refining delicately and patiently till it consolidates. While it is hardening he works diligently, retouching it continually with moistened paint-brushes in such a manner as may bring it to perfection, just as if it were of wax or clay. By means of this same arrangement of nails and of ironwork made on purpose, larger and smaller according to need, vaults and partition walls and old buildings are decorated with stucco, as one sees all over Italy at the present day to be the habit of many masters who have given themselves to this practice. Nor is one to suspect work so done of being perishable; on the contrary it lasts for ever, and hardens so well as time goes on, that it becomes like marble.