The Practice of
Tempera Painting - How Fields of Metal
May be Used in Pictorial Design (cont.)

Faulting
When you are getting the ground gilded, do not pay too much attention to any little faults or breaks or omissions in the gilding. They are easily repaired after the main work is done. If you happen to have a scrap of gold to fit a fault, you may put it on, certainly: but stopping to fault [as repairing of this sort is called] disturbs the tempo of the gilding, and slows down the work. It is better to postpone the faulting to the end. If you have accumulated a lot of little scraps of gold in the back of your cushion, they may be used for faulting. Otherwise, cut a leaf into narrow strips, and each strip into such little pieces as you find you need. Then, either with the tip or with a brush handle wrapped in a wisp of absorbent cotton and lightly moistened with your lips, pick up these little squares of gold, one by one; and set them in place upon the panel, breathing on the surrounding gold until it is damp from condensed moisture, and pressing each little patch down promptly with a bit of cotton. Obviously, in a warm room it will sometimes be impossible to rely on condensation, and you will have to wet the place for each patch slightly with the brush; but when you can do it with our breath alone, it makes a neater job. [p. 66]

Burnishing
The panel is now gilded; and it must be covered with a clean cloth and set aside to dry before it can be burnished. It seems to do no harm to dry it, at this stage, in a gentle draught, even of warm air. Hot air, directly on the surface, will make it crack; and no doubt the more gradual the drying, the better. In America, in a steam heated studio, an hour or two is sometimes enough to dry [p. 66] gilding for burnishing; while in England, in winter, the gesso is sometimes too soft to stand the pressure of the burnisher after two days of drying. It is desirable to burnish as soon as you can do so safely; but the advantages of burnishing early are not by any means equal to the disaster caused by burnishing too soon, and it is a good plan to allow a generous time for drying. If you tap the dry gesso with a burnisher, it gives a sharp click. When you tap a piece of fresh gilding, still damp, it gives a dull sound; but as it dries the result of tapping changes back to the sharp click. This is perhaps as good a test as any; but it does not guard against the possibility that some spots may be damper than others. The only safe precaution is to begin burnishing so carefully that if there is a damp spot, you will not be pressing hard enough to make a serious mark. [pp. 66-67]

Varieties of Burnisher
The burnishers commonest in modern trade are made of agate or flint, and they are perfectly satisfactory. Cennino's were made of hematite for the large sizes, and of animals' teeth for the small burnishers. Hematite burnishers are still made, to some extent, for book-edge gilders, and the edge-gilder's burnisher is exactly what one wants for burnishing the flat of a panel--a broad, straight, thin burnisher mounted on a strong handle, long enough to reach your shoulder. With this you can apply the pressure necessary to produce a really perfect burnish. Failing this, almost any burnisher, except the little points made for china painters, can be made to do; but the straighter the burnishing surface, the more beautifully metallic you can make your flat of gold.

As soon as you decide, by tapping, that the gold is ready to be burnished, take a burnisher, and work lightly over the gold with a circular motion and no positive pressure at all. The point of this is [p. 67] to detect any little grit or roughness, and damp spot, or danger of that sort, and to get the surface a little bit inclined to take the harder burnishing later on. It is not a bad plan to rub a little beeswax [genuine!] on a piece of soft leather, and wipe the gold over gently with this before you burnish. The slight trace of beeswax which this leaves makes the burnishing a little easier, and also a little safer; but it is not at all necessary.

Follow the first rotary very gentle burnishing by a somewhat harder burnishing, with the strokes all running one way. Do not let the strokes of the burnisher be random, but work over the whole surface with one kind of stroke, running in one way. Then, increasing the pressure slightly, burnish the whole surface again with strokes running another way, perhaps at right angles to the first, perhaps at other angles. The effect of this sort of regularity in the burnishing is not apparent until it is done; but it is an important part of good gilding. Of course, on carved portions, or pastiglia ornaments, you will burnish according to the form. Pastiglia can be shaped up and improved by the burnishing, to some extent. It should be burnished entirely. Carved ornaments, on the other hand, are often burnished partially, on the tops, as if they were of dull gold polished on the tops through wear. Burnishing should be carried as far as it will go. This means coming back to it a few days later, and putting on the final burnish after the ground has set really hard. The first burnish always goes a little dull, and needs to be gone over in this way. Any imperfections in the gilding which appear during the burnishing can still be repaired by breathing on the surface, laying fresh gold, pressing down with the cotton, and, after a moment, burnishing. [pp. 67-68]

Stamping and Graining
The panel gilded and burnished, it remains to speak of the possibility of embellishing the gilding further, and strengthening its metallic quality, by the use of impressed ornament. This served an important purpose in Cennino's day; for the haloes of the saints were distinguished in the gold grounds of paintings by tools pressed or beaten into the gold. The plane surface of burnished [p. 68] gold is something like a mirror. It looks, for the most part, uniformly dark or uniformly light. If it is broken up to parts by the use of stamps, the parts so treated possess different properties of reflection from the plane surface, and tend to look bright when that looks dark, and vice versa. Haloes were swung with compasses, which pressed thin circular grooves into the gold, and they were then ornamented with lines pressed in with a stylus and with figured punches. These punches were generally simple: rings of various sizes, points to correspond, sometimes clusters of points or rings, and occasionally some fancy forms, floral, or geometric, or architectural. These simple elements were combined with great ingenuity into beautiful and appropriate patterns. [pp. 68-69]

Punch Cutting
If a modern painter feels that he can make good use of this branch of technique, it is not difficult to make tools for the purpose. No modern application of this kind of work has been attempted by painters, except in imitation of the old, and the field is open for invention and experiment. It is a simple matter, given a length of brass rod, a vice, a hack saw, a metal file, one or two needle files such as jewelers use [round, square, triangular, etc.], sandpaper, emery cloth, and a few bits of tool steel for counter-punches, to manufacture punches of any design. To make a ring punch, for example, you simply file a sharp round point on a steel rod, and polish it with a strip of emery cloth; cut a three-inch piece off a brass rod; and drive the steel counter-punch into the end of the brass rod far enough to make the center of the ring punch of the right diameter. [p. 69] Take the file, and file away the outside of the brass rod an inch or so down from the point until the ring is left on its face in the proper thickness. Polish the end with sandpaper and emery cloth, and shape it exactly with the file and those abrasives. Test it by holding it in a smoky flame and pressing it on white paper which you have damped by breathing on it. You can make the tiniest ring graining tool in this way, for making an all-over grain on the gold, or large rings to be combined in ornaments. Other tools are made in much the same way. For some, a steel burin will be needed to cut out the pattern. For complicated tools, if they are wanted, you may need to arrange a magnifying glass over the vice; and this is easily contrived with a chemist's flask holder and stand. It is almost necessary to make the tools yourself; for leather workers and bookbinders, who use tools of this sort, want only much larger, coarser elements than are good for this purpose.

These punches are most conveniently made, as described above, on short rods [whether of brass or steel makes no difference]; for to apply them to the gilded surface, you strike them sharply with a flat strip of hard wood, and no handle is required. The smaller the face of the punch, the lighter the stroke it takes; while a large or complicated punch may need a powerful blow to press it into the gilded gesso. [pp. 69-70]

Graining Pastiglia
Pastiglia ornaments are much improved and made more effective if the elements of the design are outlined with a line of dots, and the background grained. Cluster tools for graining are tempting, as providing a quick effect; but they are never so satisfactory [p. 70] as the single tools. I favor the use of a very small ring punch for putting a uniform grain over an area of burnished gold, whether at a background for pastiglia ornament or designs drawn in the plane surface with a stylus, or as a ground to be used in combination with color in the following way [see the document: Patterns in color and gold]. [pp. 70-71]

Patterns in Color and Gold
If you lay over a field of burnished metal a solid coat of opaque or transparent color, tempered with egg as if for painting, and let it dry, you can scrape away the color with a wooden point and show the gold underneath; and you can form in this way any pattern of gold and color you please. When the color is properly tempered, it comes away as smoothly and neatly as an etching ground, and in very much the same way. An orange-wood manicure stick is a good tool to use for this work; and the color which is left on the gold should be given either a coat of weak size or one or two coats of charcoal fixative, or very weak shellac, to keep it from being rubbed off accidentally.

An inscription in gold on a field of color can be executed easily and beautifully in this method, or figures of any sort in gold and color. It is often applicable to the rendering of textiles, figured or threaded with metal. Large-scale patterns of color and gold are of course, simply executed with the brush after the gilding is done, and the edges trued up with the wooden stylus. But the use of this sgraffito method may be extended widely. You may, for example, lay a ground of white on the gold, and take out certain fields with the wooden point, leaving a pattern in white and gold; then glaze the whole pattern with viridian, and take out part of it again in gold with the point. This will produce a pattern in white-glazed-green, [p. 71] gold-glazed-green, and gold. The decorative possibilities of this method are largely unexplored in modern times, and should be worth investigating.

In practicing it, it will usually be found that the gold which is uncovered, though bright, is not effective as gold in the small areas in which it is exposed. If the uncovered portions are grained, "frosted," with a small ring punch or other tool, they catch the light and sparkle, and play a much more striking part in the design. By graining them in some parts, and leaving them flat in others, these areas of gold surrounded by color can be given a wide variety of agreeable effects. When gold and palladium are used together in the underlying ground, the range of effects of color and metal is, of course, still further increased.

Burnished metals in the scheme of painting have been used in the past with great success; and there are some indications that the modern painter may find new ways to make good use of them. Tooling the surface of these areas of metal is a natural consequence of their solid appearance. The use of pressed-in and stamped-in ornament develops their power of reflecting light, gives them variety, and forms a legitimate addition to the elements of the design. This sort of ornament increases the illusion of thickness in the metals, and makes it still more urgent that these metallic surfaces be used by the designer as if they were not leaf but massive gold and silver.

Still further resemblance to massive metal results from the process for producing damascene effects invented by Professor Lewis York, and reported by him in Technical Studies in the Field of the Fine Arts, II [1933], 105, 106. Professor York's original paper is reprinted here, with his consent, by permission of Technical Studies. [pp. 71-72]

Combination Gold and Silver Leafing
When a figure in silver is wanted on a gold ground, or conversely, both metals to be laid in burnished leaf, sharply separated, good results may be obtained by the following process. First lay and burnish the silver leaf; then paint over the already burnished silver with a rubber cement up to the edge desired. When the cement is dry, the gold leaf is laid over the whole area enclosed within the outline formed by the edge of the cement. When the gold is laid, it should, of course, be allowed to overlap the edge of the cement itself. As soon as the gold is ready to burnish, the rubber cement and excess leaf can easily be rolled up into a little ball with the finger, leaving the gold in the desired pattern on the ground of silver and ready to be burnished.

Various applications of this method may suggest themselves--backgrounds figured in the two metals, patterned draperies, armor, inscriptions, etc. When silver leaf is used it will tarnish unless protected by a lacquer of some sort. In certain cases the effect of the darkened silver in contrast to the unchanged gold may be utilized to good effect. When this is not desirable, a permanent burnished silver quality may be obtained by the use of palladium leaf, which has lately become available in commerce. The color of palladium differs somewhat from that of silver: it is a little dark and leaden in comparision, but only a very critical eye will detect the substitution. [p. 73]