Master Class - advanced oil painting principles and techniques from the Renaissance to the present
by Virgil Elliott, APSC, ASPA
TECHNIQUES OF PAINTING IN OILS
From the earliest days of oil painting to the time of this writing (late Twentieth Century, into the early Twenty-first), a number of oil painting techniques have evolved.
A great deal has been learned through the processes of trial and error and from the experiments of various artists through the centuries. From Jan and Hubert Van Eyck, possibly the first innovators to paint pictures in oils, in the late Fourteenth and early Fifteenth Century, to William Bouguereau, Jean Léon Gérôme, Alexandre Cabanel, Jehan-Georges Vibert and the other French Academic painters in the late Nineteenth Century, technical knowledge developed more or less continuously, as artists of each generation added their discoveries to what their predecessors had learned.
The continuity was interrupted around the end of the Nineteenth Century as a result of the popularity of the Impressionists, who were viewed as a rebellion against the academic style of painting. The emotional reaction to the Impressionists' emergence resulted in a total rejection of the Academy and all it stood for, to the detriment of art instruction throughout the Twentieth Century. The techniques taught at the Academy and the ateliers of the Academics represented the culmination of at least five hundred years of more or less continuous development in representational drawing and painting, dating back to the early Renaissance. This wealth of knowledge included many of the discoveries of the Old Masters, yet it was suddenly regarded as "old fashioned," “passé,” etc., and therefore of no further interest. Technical development essentially ceased at that point. Fortunately, a few of the dedicated students of the Academics carried on in obscurity, and passed what they had been taught on to their students.
There was also enough written documentation of the older techniques to enable this author, and a few other similarly obsessed individuals, to gain some understanding of what was involved, undaunted by the best efforts of several universities' art departments to discourage the pursuit of this knowledge. These written clues made possible a more thorough reading of the paintings themselves, sought out in museums across Europe and the United States over many years. Conservation scientists have also been able to provide a considerable amount of extremely valuable information previously only guessed at, which has helped to unravel the mysteries of the past, as technological advances and ongoing scientific inquiry continue to provide an ever-sounder base of knowledge from which to operate.
Only after considerable practice in painting (below) can one fully understand what is there to be read in the paintings of the Great Masters and in the books which attempt to explain the techniques (including this one).
The hope is that this book will prove a little less cryptic (and more accurate) than the old manuscripts which the author was compelled to seek out and decipher in his own quest for knowledge. It is further hoped that it will find its way into the hands of others sharing the same obsession, and help to reestablish a link with the Great Art of earlier times.
THE FLEMISH TECHNIQUE
The earliest oil painting method evolved from the earlier discipline of egg tempera painting, as an attempt to overcome the difficulties and limitations inherent in that medium. As this took place initially in Flanders, the method is referred to as the Flemish Technique.
Essential to this method of painting are a rigid surface primed pure white, and a very precise line drawing. The Flemish painted on wood panels primed with a glue chalk ground, which caused the transparent passages to glow with warmth from beneath the surface of the paint. As this method did not easily accommodate corrections once the painting was under way, it was necessary to work out the idea for the picture with studies done on separate surfaces.
The completed drawing was then transferred to the white panel by perforating the "cartoon", or a tracing of it, along its lines, then positioning it over the panel and slapping it with a pounce bag, or sock filled with charcoal dust. The stencil was then removed, and the drawing finished freehand. Another method for the transfer was to cover one side of a piece of tracing paper with charcoal, or with a thin layer of pigment and varnish or oil, which was then allowed to become tacky, and use it as one might use carbon paper.
Once the drawing was transferred to the primed panel and completed, its lines were gone over with ink or very thin paint, either egg tempera, distemper (glue tempera), watercolor or oil, applied with a pen or small, pointed, sable brush, and allowed to dry. The drawing was then isolated, and the absorbency of the gesso sealed, by a layer of varnish. Sometimes a transparent toner was added to this layer of varnish, which was then called an imprimatura. The tone of the imprimatura set the key for the painting, making the harmonization of the colors easier, and allowing for more accurate judgment of values. A field of white primer tends to make everything applied to it appear darker than it is, until the white is completely covered, at which time the darks are sometimes seen to be too light. And when the darks are too light, generally the rest of the tones are too light as well. By toning the isolating varnish (a warm tone was most commonly used), to a tone somewhat darker than white, this problem could be avoided or minimized.
Once the isolating varnish or imprimatura was dry, painting commenced with the application of transparent glazes for the shadows. The paints used by the early Flemish practitioners were powdered pigments ground in walnut or linseed oil. There is widespread speculation regarding whether other ingredients, such as resins, balsams, and/or various polymerized oils were added, and the issue is not yet resolved as of this writing. All opinions on this subject must be understood to be guesswork until scientific analyses have been completed on enough paintings from this era to settle the issue. It is likely, though not definitely established, that the brushing characteristics of the paints might have been altered to a long molecular configuration by the addition of boiled or sun-thickened oils, and possibly balsams such as Strasbourg Turpentine or Venice Turpentine, and/or resins. Strasbourg Turpentine, sap from the firs growing in and around what is today Alsace Lorraine and elsewhere in Europe, is similar to Venice Turpentine but clearer and faster drying. Balsams and polymerized oils add an enamel like consistency to oil paint, changing its structure to a long molecular configuration. Long paint is easier to control than short paint, especially with soft hair brushes on a smooth painting surface, as in the Flemish Technique. Brushes used by the early Flemish oil painters were primarily soft hair rounds. Some were pointed at the tip; some were rounded, and some flat. Hog-bristle brushes were also used for certain purposes, such as scrubbing the paint on in thin layers for glazing and other effects.
Painting commenced with the laying in of shadows and other dark shapes with transparent paint. In this method, the painting is carried as far along as possible while the paint is wet, but is usually not finished in one sitting. Large areas of color are applied after the shadows are laid in, and worked together at the edges. These middletone colors may be either transparent, opaque, or somewhere in between, depending on the artist's preference. The highlights are added last, and are always opaque. Several subsequent overpaintings may be applied after the initial coat is dry, if desired. Some Flemish artists also employed an underpainting of egg tempera, or egg oil emulsion paint, to help establish the forms before painting over them in oils.
The Flemish method, in summary, consists of transparent shadows and opaque highlights, over a precise line drawing, on wood panels primed pure white. The painting medium may possibly contain a resin and/or balsam, which increases clarity and gloss, or a combination of a polymerized oil with a raw oil, which takes on the most desirable characteristics of a resin when used together (i.e., sun-thickened linseed or walnut oil, plus raw linseed or walnut oil, mixed together), without the defects of natural resins. The innovations are the use of oil paint and the technique of glazing with transparent color. A glossy varnish is applied at least six months after completion. Paintings are generally limited to smaller sizes, due to the difficulties involved in constructing, priming, and transporting wooden panels of greater dimensions. It had its limitations, but was a vast improvement over egg tempera, both in ease of execution and in the beauty of the final result.
Although it originated in Flanders, word quickly spread of the marvels of oil painting, and it was soon adopted by the German artist Albrecht Dürer, who is known to have traveled to Flanders and to Italy, and by Antonello da Messina, who studied in Flanders, according to Vasari. Giovanni Bellini then learned it from Antonello, and taught it to Giorgione and Titian. The Flemish painter Rogier van der Weyden, who was adept at painting in oils, came to Italy around 1449 and influenced a number of Italian artists, including Piero della Francesca. The use of oil as a painting medium was adopted cautiously by some, and derided by others, as anything new always seems to create controversy. Michelangelo refused to paint in oils, and reportedly ridiculed Leonardo for adopting it. Titian (Tiziano Vecellio) recognized its merits, and soon added several innovations of his own.
THE VENETIAN TECHNIQUE
Titian and Giorgione are generally credited with originating what became known as the Venetian Method of oil painting. The Venetian Method, or Venetian Technique, shares with the Flemish Method the use of transparent glazes for the shadows, darker darks and for certain special effects, and opaque highlights, but differs from the Flemish method in several important ways.
The method evolved out of necessity, as the church desired large paintings of religious scenes for cathedrals, and wealthy dukes wished to adorn their palaces with large paintings of mythological themes and other subjects. The difficulties of constructing and transporting huge wooden panels influenced artists to seek an alternative. Canvas was soon adopted as the most convenient support for large paintings, as it could be rolled up and delivered, then reattached to the stretcher frame, or another of the same dimensions, at the painting’s destination and hung. However, the rough texture of the cloth created a need for certain adjustments in technique and perhaps in the chemistry of the paints. A new primer was also needed, as gesso (gypsum bound with animal glue) and glue/chalk grounds are brittle, and thus unsuitable for use on a flexible support. After years of experimentation, involving the addition of oil or honey to gesso to render it more flexible, white lead ground in linseed oil became the accepted primer for canvas. The canvas was first given an application of weak glue sizing to render it nonabsorbent, as the linseed oil would have otherwise caused the canvas to rot. The glue sealed the absorbency of the canvas and excluded the oil from the linen or hemp fibers.
The gloss inherent in paints formulated for the Flemish Method was found to be objectionable for large paintings, and Titian seems to have made adjustments to produce a less reflective surface. It is likely he eschewed the use of polymerized oils, balsams and resins, all of which increase gloss, and opted instead for simpler paints ground in raw oil only. Thus the paint would have been of a short molecular configuration, rather than the (presumably) long paints of the Flemish. It was found that stiff, hog bristle brushes worked better with the short paint and rough textured canvas.
The combination of large, stiff brushes, short paint, and the tooth of the canvas made the painting of hard edges more difficult. Sharp edges occur quite naturally in the Flemish Technique, with its smooth surface, long paint and soft hair brushes, whereas the stiff brushes and short paint produced soft edges as a normal result on a coarse textured canvas. Titian (or perhaps Giorgione, who died young), however, apparently found the softer edges more to his liking, and used them extensively, as they gave the effect of being slightly out of focus. The edges could be sharpened selectively, where desired, to call the viewer's attention to an area of greater importance, or to describe an object whose edges were actually sharp, such as a starched collar, sword, or piece of paper or parchment, or they could be left soft in the interest of Selective Focus.
The systematic use of soft and hard edges together gave the paintings a more lifelike appearance, and more closely approximated the visual experience than did the overall use of hard edges, as had been the previous practice. Titian was perhaps not quite as accomplished a draftsman as Michelangelo, who is said to have criticized him for it, so he devised a technique which allowed him greater latitude for corrections. This technique involved the use of an opaque underpainting, with the edges left soft and nebulous to allow for later adjustments where necessary. Once the forms were established to the artist's satisfaction, he would allow the underpainting to dry, while he worked on other paintings. When dry, the underpainting could then be painted over in color, beginning with the transparent glazes for the shadow areas, as in the Flemish Technique, and developed further with opaque passages representing the areas of light.
In the Venetian Technique, color is often applied over the underpainting initially as transparent glazes, which are then worked into, while wet, with opaque pigments. The paint is worked together wet into wet until the desired effect is achieved, or until the paint becomes slightly tacky, at which time it is allowed to dry thoroughly. This process may be repeated as many times as necessary.
At some point, someone, perhaps Titian, discovered that a light, opaque tone, rendered semitransparent by the addition of a bit more oil and/or simply by scrubbing it on thinly with a stiff brush, applied over a darker area produced an effect that could be put to good use. This is what we now call a scumble. It was found that a scumble over a flesh tone would produce the same effect as powder on a woman's face; that is, it made its texture appear softer. This is a useful device when painting women and young people of both sexes. It is also useful for indicating atmospheric density over distance, or atmospheric perspective. See Chapter Five, Principles of Visual Reality.
Both glazing and scumbling create optical illusions. As such they effectively expand the capabilities of the limited palette of the early painters in oil. It was imperative that they get the most out of the materials they had.
Glazing is the application of a darker transparent paint over a lighter area. The optical illusion created by the light rays’ having passed through a transparent darker layer, bouncing off the lighter surface underneath, then traveling back through the transparent layer to the viewer’s eyes, is unique to glazing, and cannot be obtained in any other manner. A warm glow is created, and the color thus produced appears warmer and more saturated (higher in chroma) than the same pigment applied more thickly and opaquely. The effect, in the darker passages, is that of a shadow seen up close, with no atmosphere between the viewer’s eyes and itself. The rich, golden glow in Rembrandt's dark browns is produced in this way. Rembrandt was influenced by Titian, and is reported to have at one time owned at least one of his paintings. Glazed darks appear darker than opaque darks, because the light rays are allowed to penetrate more deeply into the paint layer, and are thus subjected to a great deal of filtration before reflecting back out to the viewer’s eyes. This effectively expands the value range possible with paints, which are handicapped on the light end of the spectrum by the fact that white paint is not as light as light in Nature. The Old Masters compensated by carrying their darks as far as they could, to create as wide a range of values as possible. This can only be accommodated through the use of transparent paints on the dark extreme. Furthermore, as light contains color, the artist must make the highlights darker than white in order to include color in them. This further limits the value range, and makes necessary the darkening of all tones by a corresponding amount in order to maintain the proper contrast and relationships between each category of light or shadow. Transparent darks allow the expansion of the dark end of the range.
Scumbling is the opposite of glazing. A scumble uses a lighter opaque paint, spread thinly enough so as to become translucent, over a darker passage. The optical effect thus produced is bluer than the paint applied, as the underlying layer is not completely obscured, and exerts its influence on the overall sensation, as has been previously described. It is very effective in softening surface textures, as soft cloth, such as velvet or cotton, or youthful complexions, the surface of a peach, etc., and, as mentioned, for indicating atmospheric haze over distant land planes and in the sky near the horizon. Overcast skies may be scumbled all over, as in Bouguereau’s “The Broken Pitcher.”
There are still more advanced and sophisticated developments of the Venetian Technique. The "semiglaze", which can be either transparent or semiopaque, or anywhere in between, is a very thin application of color to an area of the same value as the paint being applied. Its purpose is to modify the color of a given area after that area is dry, as in the addition of a tiny bit of vermilion to a cheek or nose, and/or to allow subsequent wet into wet painting over an area in which the paint has dried. It tends to soften unintended too-harsh transitions of tone from the previous sitting, if used properly, and thereby adds a higher degree of refinement to the image. It is applied thinly, by scrubbing it on with a stiff brush, after the addition of a small amount of oil or a painting medium to lubricate the dry surface of the area to be repainted. Titian is reported to have sometimes applied glazes and semiglazes with his fingers, or perhaps he was wiping the excess away after having put too much on with a brush. Stippling with a flat tipped brush is a good technique for applying glazes, scumbles, and semiglazes, though other means work very well in skilled hands.
As a further development of the Venetian Technique, the underpainting, or certain parts of it, may be executed in opaque color, rather than totally in neutral greys. One popular variation was Venetian Red and Flake White. The underpainting palette should be limited to lean paints (paints with low oil absorption) which are opaque and/or very high in tinting strength. High tinting strength fat paints (paints with high oil absorption) may be used if mixed in very small quantities with very lean paints like Flake White. The objective is to keep the underpainting leaner than the layers applied over it. When dry, the color may then be subsequently modified with glazes, scumbles, and semiglazes, or painted over with opaque color. These steps may be repeated as many times as necessary. The highlights are placed last, applied wet into wet with a fully loaded brush. Impasto is often employed in the highlights, to produce the most opaque passages possible, and to ensure that they remain opaque. Oil paints become more transparent with age. Therefore, in order for the highlights to retain their opacity over the centuries, they must be applied heavily. The illusion thus created is that of direct light falling on a solid surface, ricocheting from that surface to our eyes. It is not actually an illusion, as that is exactly what is happening. Juxtaposed with the transparent shadows, the illusion of depth is thus enhanced.
The underpainting, sometimes referred to as a grisaille if done in greys, should have its darkest passages painted somewhat lighter than the desired final effect, or the superimposed colors will lose much of their brightness and depth . Except for certain special effects, as in the technique of Rembrandt, the texture of the underpainting should be as smooth as possible. Any brushstrokes not smoothed out before the underpainting is dry, or scraped down before painting over, will produce a problem area in the next stage. Artists who prefer visible brushstrokes should decide where to place them in the final stages of the painting, as accents.
The Venetian Technique allows the widest range of possibilities of any oil painting method yet developed. Its systematic use of opaque passages, glazes, scumbles and semiglazes stretches the capabilities of oil paint to the absolute limits, and allows the artist the greatest latitude for adjusting the picture at any stage. The employment of the optical illusions created by glazing and scumbling, combined with the control of edges (selective focus), enables the oil painter who has mastered it to indicate three dimensional reality more convincingly than is possible with any other technique.
Among the Old Masters who used the Venetian Technique in one variant or another were Rembrandt, Franz Hals, Nicholas Poussin, Jacques Louis David, Jean Auguste Dominique Ingres, Jean Léon Gérôme, and many other great Masters whose names are not well known today.
It should be stressed that the wonderful results achieved by the Old Masters and other great painters were attributable, in great measure, to the preparations undertaken prior to their beginning work on the final canvas or panel. The concept for the painting had first to be worked out in smaller drawings, sketches and studies done on separate surfaces, to solve all the problems to the artist's satisfaction beforehand. This accounts for the impression most often conveyed by their paintings, of having been executed without the necessity of corrections. In truth, there were many corrections, but the major ones, at least, were most often solved in the study stage before the painting itself was touched.
For very large paintings, the usual practice was for the Master to paint the painting first on a smaller scale to work out its composition, and then turn it over to his apprentices to be transferred to the large canvas by means of a grid. Refer to the sidebar for a more detailed description of the grid method of enlarging a design. In some cases, the smaller painting was done without color, to be used by the apprentices as a guide in applying the underpainting to the large canvas, which process the Master would oversee, and usually correct and complete after the students and/or apprentices had done most of the work. Often many supplemental studies were drawn and painted by the Master, either to aid the assistants in painting the large picture, or to solve some of the problems for himself, in the development of the concept for the painting. This practice is as much a factor in the excellent quality of the works these great painters produced as were the actual painting techniques they used so well.
The Direct Painting Method differs from the Venetian Technique and the Flemish Technique in that the artist paints in full color from the very beginning, without requiring an elaborate under drawing or underpainting, and without resorting to the use of glazes or scumbles. All paints except the deepest darks are used as if they were opaque, and are usually applied heavily enough as to appear so. The object, ideally, is to paint the entire picture wet into wet, from start to finish. Terms such as Alla Prima (Italian) or Premier Coup (French) are sometimes used for this technique, indicating that the picture is to consist of one layer of paint, applied all at once, in one sitting. In practice, this is not always possible, and great pains must then be taken to nonetheless make it appear as if it were done alla prima.
The Old Masters employed this technique for sketches only, to be used as visual aids in the creation of larger works executed following the Venetian method or a variant. Franz Hals was the first painter to use direct painting for other than sketches, although the works for which he is famous today may still arguably be called sketches. Hals was proficient in the Venetian Technique as well, and used it for his commissioned portraits. The Direct Painting technique was elevated to legitimacy in the Nineteenth Century by Carolus Duran, the teacher of John Singer Sargent, and then by Sargent himself, among others, most notably Anders Zorn, Cecelia Beaux, and Joachin Sorolla y Bastida.
The range of effects possible with Direct Painting was once much narrower than with the Venetian Technique, but today's wider selection of pigments has expanded its possibilities considerably over what was available in earlier times. The invention of the cadmium pigments and synthetic ultramarine in the Nineteenth Century made Direct Painting a more viable alternative to the Venetian Technique.
Individual approaches vary greatly. Some prefer to begin in charcoal, with a few quick guidelines sketched freehand on the canvas before beginning to paint, while others choose to begin immediately with the brush, and sketch in the shapes initially with thin paint indicating the shadow masses. Some painters tone the canvas beforehand with a very thin transparent imprimatura, to "kill the white", which might otherwise influence them to paint their darks too light a value, and some prefer to paint directly on the white canvas. Others tint the primer to a value darker than white by adding paint or pigment to the final coat of primer to make an opaque tone somewhat darker than white.
A toned ground or imprimatura makes judgment of values a bit easier. Painting on an opaque primer darker than a value seven on the Munsell scale will make the superimposed colors duller, however, and will cause the painting to darken in time. It is better to use a white primer, and add a transparent tone over it to lower the value initially, or add a light opaque tone over the white primer. A transparent toner can be painted into immediately, or allowed to dry before commencing. With the latter practice, care must be taken to avoid violating the "fat over lean" rule.
As with the Flemish and Venetian methods, darks should be applied first, and thinly. The reason for this is that the shapes are indicated reasonably well with just the dark shapes and shadows, and corrections may be made without excessive paint buildup by simply wiping out mistakes with a rag. The early stages are most likely to require correction of shapes, so it is prudent to begin thinly. This also allows a certain degree of transparence in the shadows, which is desirable. Oil paint is most easily controlled by painting wet into wet, from dark to light, systematically. As the reader has surely discovered at one time or another, to attempt to indicate a shape haphazardly, beginning with a middletone or light color soon results in a sea of wet paint into which everything disappears as soon as it is applied. This is called mud. The mud experience has discouraged many would be oil painters over the years. It is simple enough to avoid, if one proceeds methodically, following a logical progression.
It is advisable to begin with a very large brush, and block in the large general shadow and other dark shapes first, correcting any mistakes by wiping with cheesecloth, used as an eraser, before adding a second color. The large color shapes in the middletones and lighter shadows should then be blocked in, using another large brush. One may then work back into the shadows and add secondary light, reflected color, and shadow accents, then return to the middletones and add refinements there, saving the lighter areas and finer details for last.
The lights should be painted more thickly than the darks. Large brushes cover more canvas in a given time, hold more paint, and allow the artist to paint much faster. The use of small brushes and the addition of detail should be forestalled as long as possible. Many agreeable effects can be created through expert use of a large brush, especially in areas in which one might be tempted to switch to a smaller one.
Facility in this style of painting is developed by the execution of studies painted from life. As they are only studies, there is no pressure to create a masterpiece, and the student is free to experiment. After a bit of practice, the studies become more and more accurate, as the student's ability to perceive value and color is developed to a higher degree, and the initial awkwardness with the brushes and paints is overcome.
It is helpful to isolate value in one's first attempts in oils, by working only with white and greys made with Ivory Black and white. Once the student is past the struggling with the paint stage and has learned to understand values, color may be introduced a little at a time, at first adding only Yellow Ochre (or Raw Sienna) and Red Ochre , for use in color sketches of the human head from life. With this palette it is possible to mix what appears to be a full range of colors. It is only effective in paintings with an overall warm tonality, in which context greys made with Ivory Black and white appear to be blue. Greens are made from yellow and black, or yellow, black, and white, and violets are mixed from black and red, or black, red, and white. An automatic unity is thus achieved, as the cool colors produced in these mixtures are low in chroma, and cannot disrupt the harmony of the warm dominance.
The palette is then expanded gradually, as the student becomes familiar with the limited palette, by the addition of Burnt Sienna, Raw Umber, and Cadmium Red, Light. At the appropriate point, Ultramarine Blue is added, and so on, so that no lesson overwhelms the student with too much to learn at once.
It must be stressed repeatedly during the early sketch sessions in oils that only the big shapes should be painted, and large brushes used exclusively. No detail should be attempted until the student is able to judge the correct value, color, shape, and relative proportions of the large shapes of shadow and light accurately. By then, the powers of observation will have been developed highly enough that the rendering of detail will be easier, and, hopefully, bad habits will have been unlearned.
By this method of learning, one gains the necessary skills for painting well in oils, in any technique.
The Direct Painting Technique is the one most widely used in modern times. The vast range of pigments available today has, in great measure, narrowed the gap between what is possible with it and with the Venetian Technique. It is also possible to modify the Direct Painting Technique by finishing off with glazes and/or scumbles after the painting is dry, but it then ceases to be direct painting. Some styles of Direct Painting owe their appeal to the painterly looseness obtained when painting very quickly with large brushes. For this type of painting, superimposition of glazes and scumbles would in most cases be inappropriate.
In practice, the boundaries between techniques become blurred as artists combine elements of more than one method in pursuit of the desired effect. This is how new techniques are born.
INNOVATIONS OF REMBRANDT
Rembrandt Harmenszoon Van Rijn, whom many consider the greatest artist of all time, learned all that was then known about oil painting while still a very young man, surpassing his teachers very early in his career, and then proceeded to add his own discoveries to the technical knowledge of his time. To this day his best works remain unsurpassed, and serve as inspiration to the rest of us who paint. This being the case, any book on advanced techniques must address Rembrandt separately and at such length as the author's knowledge allows.
What technical information Rembrandt was taught may be discerned by studying the works of his instructors, Jacob Isaacxszoon Van Swanenburch and Pieter Lastmann. Such study also immediately shows the genius of Rembrandt by the extent to which he so obviously surpassed them both, and in how early in his career he did so. Nonetheless, his training under them was an important factor in his artistic development, and should not be minimized. Both teachers seem to have possessed a working knowledge of the painting methods in use at that time, which Rembrandt learned from them. This would include the Flemish Technique, the Venetian Technique, and the Direct Painting Technique. Various examples of his work show that he was not limited to any one of them, but employed them all, the choice depending on which approach best suited the subject in question, and for what purpose the painting was intended. His facility with all three soon led him to combine aspects of one with another, and to add innovations of his own.
Some of his paintings are on wood, executed in what appears to be essentially the Flemish Technique; some small studies on wood panels were done in a variation of the Direct Painting Technique, and some on canvas in both the Venetian and Direct techniques. The primer for the panels is white, the first coat consisting of glue chalk gesso, which was sanded to smooth out the irregularities of the panel’s surface, then a layer of white lead in linseed oil, sometimes tinted with black, Raw Umber, and sometimes an earth red, covered with a transparent brown imprimatura, which creates the golden glow characteristic of his work. His canvases are primed with an underlayer of a red earth, perhaps to fill the texture of the canvas, then overlaid with a light, warm grey made from lootwit (lead white with chalk, ground in linseed oil) and Raw Umber, sometimes with a little black and/or earth red, or sometimes with white lead alone.
Rembrandt was an extremely versatile artist, and did not likely follow an unthinking repetition of the same procedure every time. Undoubtedly he thought his way through each painting, from the genesis of the idea to the last brushstroke, never lapsing into a routine approach. From unfinished pictures we know that, at least sometimes, he began in transparent browns, working in monochrome to establish the design of the picture, attending to the masses of dark and light, often using opaque white for the strongest lights in this stage, sometimes referred to as the imprimatura, or later, by the French academic painters, as a frottée, though the term, “frottée” generally referred to a thin brown scrub-in without white, the lights instead being simply indicated by leaving the light ground more or less exposed. This stage was apparently allowed to dry before proceeding further, though there may well have been exceptions. Over the dried brown underpainting color was begun, with Rembrandt working from back to front rather than working over the whole picture at once. He exploited to the fullest the qualities of transparence and opacity, relying on the underglow of light coming through transparent color for many special effects, with opaque lights built up more heavily for the brightly lit areas, their colors sometimes modified by subtle glazes, semiglazes or scumbles, and the arrangement of transparent darks and opaque lights to play against one another for maximum visual impact and depth.
Clues as to his choice of primer may be seen in areas where he has used a sharpened brush handle to scratch through wet paint in order to indicate bits of hair. This is evident in a very early self portrait, now in The Hague, and in many other portraits. The primers and/or imprimaturas thus revealed show that he followed no one single procedure, but varied the choices, based on the effect he was after. The scratching with a sharpened brush handle into wet paint was one of his earlier innovations.
Not long afterward, he began building up the opaque passages in his lights more heavily, and texturing them to take on the physical convolutions of the lighted surfaces of his subjects, most notably the skin textures of male subjects, including himself. The texture was created, or at any rate, can be duplicated, by applying the paint somewhat heavily with large brushes, then gently passing a large, dry, soft hair brush over the surface of the wet paint, back and forth, until the desired texture is attained. Rembrandt began to superimpose glazes of red over these textured passages when dry, then wipe them off with a rag, leaving traces remaining in the low spots to create an even more convincing texture of rough flesh. Someone, at some point, said you could pick up a Rembrandt portrait by the nose.
As he began to expand the effect of glazing over dried impasto to other textures as well, he devised a method employing two whites; one for impasto and one for smoother passages. The impasto white was faster drying, probably made so by the addition of egg (traces of protein, presumed to be from egg, have been found in samples analyzed by conservation scientists), and ground glass, into the formulation. It was very lean, and consisted mostly of white lead with a minimum of binder. He began applying it more and more heavily as the first stage of a two (or more) stage operation which was finished with transparent glazes and wiping, to create fantastic special effects, the most extreme example of which is the man's glowing, golden sleeve in the painting referred to as "The Jewish Bride," in the Rijksmuseum in Amsterdam. The brilliance of this effect cannot be gotten in any other way. He has used the same technique on the bride's costume in the same painting, but here the underpainting is red, which is deepened with a glaze of red lake, probably Carmine (Cochineal). The red carpet on the table in "The Syndics of the Drapers' Guild" (sometimes called "The Dutch Masters"), also in the Rijksmuseum, is done in much the same way. The underpaint appears to have been trowelled on with a knife or some sort of flat stick, then sculpted before it dried.
In Lieutenant Ruytenburch’s uniform in "The Night Watch," Rembrandt used this method, but with less heavy impasto, for the ornate brocade work. The wet underlayer was worked with sharpened brush handles and other tools while soft, then allowed to dry before applying the darker glazes. By wiping the glazes off as soon as they were applied, Rembrandt was able to create a bas relief effect of remarkable three dimensionality as the glaze remained in the nooks and crannies. By glazing again, this time with transparent yellows and/or browns, instead of Ivory Black, he gave the textures a rich, golden glow.
Scientific analyses carried out by the National Gallery, London, show that Rembrandt added body to his glaze-like passages by mixing in a bit of chalk, which functions as an inert pigment essentially transparent when mixed with oil, and ground glass, which was probably used primarily to accelerate drying. The glass most likely would have contained lead and/or cobalt, both drying agents.
There has been a great deal of speculation as to what medium or media Rembrandt used, with most of the theories stating that one resin or another had to have been a major component. It now appears that these hypotheses may be in error. Recent studies of paint samples taken from a number of Rembrandt’s paintings show no detectable resins. In most of the samples tested, only linseed oil was found, and walnut oil in some of the whites and blues. In some cases some of the oil was “heat-bodied,” as in perhaps boiled or sun-thickened linseed oil. It is probable that these were added to the paints in which he wanted a long brushing quality, and in at least some of his glazes. The combination of polymerized oil and raw oil produces a resin-like substance without the undesirable properties of resins. Reinforced with chalk for body, and ground glass for faster drying and perhaps transparency, these appear to comprise Rembrandt’s glazing media, as nearly as is discernible by the present level of scientific knowledge, which, it must be noted, is subject to change at any time, as new discoveries are made. For paints intended to be blended smoothly and opaquely, it is most likely that no medium was added, beyond the linseed or walnut oil in which the pigments were ground.
Rembrandt had at least one life size jointed mannequin, on which he would pose the clothes of his sitters. The mannequin, unlike a living person, would remain motionless for as long as Rembrandt needed to paint the clothing, the folds remaining undisturbed for days, or weeks, if necessary. A live sitter would have to visit the bathroom, eat, sleep, move around, etc., and the folds of the cloth would never be likely to resume their previous shape after any of these activities. The use of the mannequin may or may not have been Rembrandt's innovation, but it was, and is, a good idea regardless.
We cannot expect to be able to rival the great genius of Rembrandt merely by following some of his procedures and using the same tools and materials he used. These are only a small part of his brilliance as an artist. At the core was his intelligence and artistic sense, his ability to constantly strive to improve upon what he had already done without losing sight of the original concept for the painting, to devise techniques, on the spot, which would create the effect he was after. We might hope to achieve the best results by adopting this same attitude towards our own work, rather than by attempting to reduce the methods of a great genius whose works we admire to a simple formula and then following it, unthinking. This is not meant to disparage technique, but to show it in its proper context. The more we know of technique, the more effects we have at our disposal, to serve our creativity and inspiration in the execution of our finest conceptions. If there is anything remotely approaching a formula for creating Great Art, it might be stated as the combination of knowledge and intuition in a single endeavor, plus a lot of work.