This method of painting had its limitations, most notably in the difficulties involved in creating larger works, and in making corrections during the painting process. The Italian artist Antonello da Messina, according to Giorgio Vasari, learned to paint in oils from Jan Van Eyck, and introduced the techniques to Giorgio Bellini, who in turn taught it to his students. It is also known that the Flemish oil painter Rogier Van der Weyden was working in Italy around the middle of the Fifteenth Century. In any case, a number of Venetian artists adopted the practice, and some subsequently altered the procedures to suit their own needs. This led to the development of the Venetian Technique.

At first the Italian painters worked in the manner of the Flemish, but when commissioned to create huge paintings for cathedrals and palaces, they began looking for ways to more easily accommodate the larger sizes. Wooden panels would not only have been extremely difficult to construct and transport but the methods of painting then in use would also have taken far too long to finish works of such gigantic proportions. There was also the problem of glare, created by the reflection of light source on the glossy surface of the picture, making large paintings harder to read. With smaller pictures this was not problematic, as the angle of incidence from a light source high above did not throw the glare into the eyes of the viewer when the paintings were hung at eye level. It was probably Titian (Tiziano Vecellio, 1487-1577) who solved these problems, one at a time, beginning with the idea of painting on canvas.

This state of the underpainting for Portrait of Emily McDonald by Virgil Elliott was preceded by two charcoal and chalk sketches on grey mat board, done from life, and a color sketch in oils, also done from life. The underpainting was begun by following the studies and finished with a live sitting. Only the flesh areas were underpainted in opaque greys.

Venice was a wealthy seaport, where canvas could be bought in large sizes for the sails of ships. By stretching canvas over a wooden framework, the artist could create a large painting in his studio, then detach it and roll it up when dry, and deliver it to the cathedral or palace where it was to hang. Once delivered, it easily could be reattached to the bars.

The glare problem necessitated a different formulation for the paints and the mediums added to them. The solution was to eliminate the resins and balsams used by the Flemish and substitute beeswax melted in walnut or linseed oil as a painting medium. This resulted in a matte surface less susceptible to glare. It also produced a different consistency and handling characteristic in the paint, which now took on a more short character, as opposed to the long molecular structure of paint containing resins, balsams and/or polymerized oils, as used by the Flemish. The terms short and long refer to the configuration of the molecules of the binders in either a round (short), or oval or oblong (long) shape, which affects the way the resulting paints handle under the brush.

Long paint will brush out like enamel and works best in conjunction with sable brushes and smooth surfaces such as panels or very tightly-woven canvas which interstices have been filled with white lead primer. The oblong molecules tend to align themselves in the direction of the brushstroke and allow the paint to flow in that direction only. This combination allows for precise control and very sharp edges.

Short paint wants to spread in every direction and works best with larger hog-bristle brushes on a canvas with a more pronounced texture. Strokes tend to have softer edges in this situation, which more readily facilitates painting following the principle of selective focus, in which areas of secondary or tertiary importance are rendered in softer focus than the areas of primary importance. It is likely that this discovery was the by-product of the adoption of canvas as a support and the abandonment of resins and balsams from the formulation of paints. Titian probably found that by varying the degree of sharpness or softness of his edges, a more convincing illusion of reality could be created than was possible by following the older practice of rendering everything sharply. This was a major step in the evolution of painting.

Titian adopted the habit of developing the design and modeling of his pictures in stages, the first of which was an underpainting in shades of grey and white. The entire picture could be painted this way if desired, or only certain passages, such as flesh and perhaps cloth, according to the artist's preference. The artist could concentrate on the design, composition, modeling, patterns of light and dark, etc., and make as many corrections as were needed, all in the grey stage, until the only problem left to be solved was color. This method avoids the "mud"which often results when corrections are made in color. The color scheme may be determined by executing as many small color sketches as might be necessary, on small panels, until the best possibility is apparent.
Once the underpainting was satisfactory, it was allowed to dry thoroughly before color was applied. Initially, the colors were blocked in transparently with large brushes, thinly so as to allow the underpainting to show through. While the transparent colors were wet, opaque colors were worked into them in the areas of light. The forms were completed as much as possible wet-into-wet in this stage, leaving the deeper darks transparent but with the lights opaque. Subsequent glazes and scumbles were often employed to further develop the forms and/or adjust the colors and values. A scumble is a thin application of a lighter semi-opaque paint over a dried darker passage. It is made of a mixture of opaque paints and transparent medium, and is used to create the illusion of softness of texture, especially in youthful complexions and soft cloth. The complex optical effect produced includes a shift in the color temperature, making the scumbled passage appear cooler. It may be considered the opposite of a glaze. A glaze is a transparent paint applied over a lighter passage. The color shift produced in glazing increases warmth. Titian was probably the first artist to use scumbling, and it was most likely his invention. Glazing was employed by the early Flemish oil painters, along with opaque passages, but scumbling does not appear until the time of Titian. Glazing and scumbling are the final refinements in the execution of a painting following the Venetian Technique. A contemporary of Titian's reported that the master often added as many as 30 or 40 glazes to a given painting before declaring it finished.

The technique was adopted by Veronese and Tintoretto, both living in Venice at the time, and it subsequently became known as the Venetian Technique, or the Venetian Method. Most, if not all, of the Old Masters of that time onward have employed it in at least some of their works. A partial list would include Rubens, Rembrandt, Franz Hals, Vermeer, Gerard ter Borch, Nicholas Poussin, Jacques-Louis David, Ingres, Jean-Leon Gerome and many other great painters whose names are less well-known today.

There are several advantages to this method of painting, not the least of which is the opportunity it affords the artist to make a great many corrections in the underpainting stage which will be undetectable in the final work. There are also the subtle influences of the underpainting, the nuances and undertones created by transparent and semitransparent passages, which, if employed in a masterly way, all contribute to a most convincing illusion of the third dimension. In portraiture it allows the artist to establish the pose, the likeness, the personality, the mood, etc., before becoming concerned with color. Once these important aspects of the portrait are taken care of, the last problem to be solved is color. It is a simpler matter to solve problems one at a time than it is all at once.

Portraiture is unique among all forms of art in that the most highly desired result is an image so convincing that it gives the viewer the impression of being in the physical presence of the subject. Artists of today can benefit greatly from the knowledge of the artists of the past, in whose works we are brought closer to the subjects than would otherwise be possible, long after they are dead and gone. To create a convincing illusion, not only of three-dimensional depth, but of a living human being, with a personality, thoughts, feelings—surely this is as close as we can get to creating magic!