FOREWORD TO AN EXHIBITION ON ART TECHNIQUES
The pictures that make this show are selected to illustrate certain technical points and not for their straight aesthetic value alone. A show stressing the technical angle should be of interest to the layman inasmuch as techniques and methods influence the aesthetic of a picture and, in the case of the collector, define the permanency of his possessions. But it is also true that to enjoy a picture one should not be overly conscious of the technical angle, in the same way that one does not need to ponder a chef’s recipes to enjoy the taste of his cooking.
The technical makeup of a painting is defined by the choice of:
A. Ground—consisting of a support and a priming.
B. Pigments and the binder with which the pigments are tempered.
C. Tools with which the pigments are applied.
The combinations possible between those three elements are numberless and thus a show—and especially one restricted in size—can but hint at the possibilities.
The material upon which a painting is executed is called the support. In this show, we find supports of textile, from the finest Chinese silk to the coarsest ixtle, burlap woven from maguey fibers; supports of wood, plywood, tin, steel, brick, paper, wire mesh and mortar, Celotex, and glass; a variety that barely suggests the infinite range of materials suitable for painting.
This support is sometimes used as is, as in the case of metal, but it is more often primed. This priming is itself often a complex affair. For example, the normal priming for a canvas to be painted in oils consists of a first coat of casein and glue to fill the pores of the canvas and to protect the painting from behind, and a second coat of oil priming that often contains white lead. The painter traditionally trained adds then a ground coat of thin pigment that can be considered as a third priming coat or the first coat of his underpainting.
Support plus priming form the ground. As the stone cutter respects perforce his stone, its grain, its hardness, its color, the painter must also collaborate with his material. This respect of objective given conditions obtains obviously in Oriental painting, where the ground, silk or paper, remains exposed and the dominant factor, while the brushstrokes are but the spice that gives to this ground all-important space properties. Though the Occidental mind has less scruples in mussing up nature, techniques such as tempera on gesso make much optical use of the ground. Oil painting more often blots out the original ground, but even there some great masters approach their material with a spirit akin to that of the Orientals.
Though one thinks nowadays of a painting as a flat rectangular object hanging vertically, paintings have been executed on the most diversely shaped grounds. In theory a concave surface is soundest as it caters to the spherical range of the focused eye. Great paintings are to be found on cylindrical surfaces––such as Greek and Mayan pottery––convex shields, and concave plates. Murals do spread over horizontal ceilings, vaulted ceilings, barrel arches, semispherical cupolas. The ground itself need not be an unbroken surface. In twelfth-century frescoes, the heads and elbows of the personages are sometimes raised at a diagonal angle to the vertical wall to catch the candlelight from underneath. The low bas-reliefs, heavily painted, of the Egyptians and Mayans offer a transition between sculpture and painting, as do the sculpto-paintings by Ozenfant and Rivera included in this show. Grounds can be inlaid with foreign objects: the metallic jewels in Pinturicchio’s frescoes, the newspapers, rope, or sandpaper favored by modern “collages.”
Pigments are the common denominator of techniques, the ingredient common to watercolor, oil, encaustic, etc. Pigments are mineral or organic, natural or artificial. Saturated as we are with an excess wealth of novel pigment discoveries, it is good to remember that Greek painting at its height used the most limited palette. Apelles used yellow and red ochre, green earth, a vine black, and those tones and their blends sufficed to fulfill the requirements of his genius. Even though not limited by usage, great masters tend continuously to a simpler palette as they grow old, as is seen in the case of Titian and Renoir. It is hard to reconcile the rainbow range of optical colors studied under artificial laboratory conditions by Chevreul and put to approximate use by Monet, with the organic knowledge of pigments that comes closer to an artisan’s approach. Certain painters intent on a permanent palette have sacrificed much optical richness for the sake of sound physical makeup, though this care is not in direct ratio of their greatness. Böcklin had staked some special plots of land in Italy from which he extracted his own ochres. Bouguereau old came to shun vermillion for the more permanent ochres. We know, on the other hand, that Watteau was careless with mixtures and that Van Gogh excused the brilliancy of his colors by hoping that time would make quick work of subduing them.
Pigments, to adhere to the ground, must be “tempered” with a binder, with the exception of true fresco where the ground, in drying, chemically procures the binding element.
Oil is the most popular medium in our time; its slow drying caters only too well to the hit-and-miss technique that is also peculiar of today. However, the “pedimenti,” changes of color and value, corrections of form, that most oil painters use remorselessly, will all emerge on the surface at a later date, for the pigment in ageing acquires increased translucency.
Quicker drying tempera (pigment ground with an emulsion) and distemper (also called glue tempera) do not allow for much fumbling. The tempera painter of today is impelled by the salutary limitations of the medium to come back to decisive drawing, sustained local color, hatched modeling––an aesthetic at variance with that of the painter in oils.
It is perhaps in fresco where the plan must be matured before execution, where lines must be traced and pounced, where colors must be put on “blind” with only a mental knowledge of what they will become, and where an objective architecture mocks all excesses of subjectivity, that the craftsman’s tradition and technical knowledge imposes more forcefully its mark on aesthetics.
Among the tools of the painter one should include the human body, of which other tools are only a working projection. A most appreciated class of Chinese ink painting is executed with the finger dipped in ink, and more than one thumb print has left its seal in the Van Gogh impasto. The diverse sets of muscles that the painter can put to work constitute a diversity of tools in themselves. Thus monumental painting will exercise muscles from the shoulder and elbow that have entirely distinct idiosyncrasies from the wrist and finger action of the miniaturist.
The use of a brush is common to most techniques, but each favors also a distinct set of tools. Ancient encaustic impasto was kneaded with heated bronze spatulas, and the modern one is surfaced with a blowtorch. Tempera on gesso may be burnished with an agate stone. Hod and trowel, squares and ruler, a pouncing roulette and a bottle to roll and smooth the surface, are all fresco accessories. Duco painters favor stencils and air brush. The youthful Cézanne painted with a spoon.
Tools become specialized insomuch as methods and aims are well defined. The Byzantine painter, the painter of the time of Giotto, obeyed recipes and painted in a series of progressive steps to each of which corresponded highly specialized instruments. Nowadays tradition still rules the craft of the house and sign painter. Lettering, wood graining, marbelizing, each implies a given tool, brush or scraper, perfect within its own limited aims. The fine-art artist of today, especially the man who paints in oil, has deviated from strict methodology; his work is more in the nature of an exploration, a kind of surprise party. With undefined aims and ever changing methods, most contemporary artists must perforce use tools of a vaguer sort, brushes and palette knife being their jacks‑of‑all‑trades.
 Foreword to an exhibition on techniques at the Penthouse Gallery of the Museum of Modern Art, New York City, 1941. Assigned title. I have omitted the parentheses in which Charlot planned to write the exhibition numbers of his examples, of which no list has survived
 Amédée Ozenfant. Diego Rivera.
 Auguste Renoir.
 EugŹne Chevreul. Claude Monet.
 Arnold Böcklin. William Bouguereau. Antoine Watteau. Vincent Van Gogh.
 Paul Cézanne.