"La Grande Odalisque" was painted by Jean Auguste Dominique Ingres in 1814.
The oil paint is thinned with some sort of oil or alkyd and painted over portions of the underpainting layer by layer. A simple analogy would be to think of colored cellophane, one sheet of yellow and one sheet of red. When placed together, the resulting color is orange. For the artist wanting to add a new dimension to her work, a return to the glazing techniques of the old masters might just be the solution.
Define
Glazing is a technique that uses two or more transparent layers of paint to achieve a new color.Glazing is a manner used by debilitated masters such as Rembrandt or Vermeer. It combines two or aggrandized obvious layers of stain, which acquire been applied over an opaque underpainting. Each transparent layer builds on the ones under them, creating new colors and added depth to a piece. While the hue may be the same as it would have been had the two colors been mixed together directly, the results are very different. Artist and writer Bill Creevy explains in "The Oil Painting Book" that it is the glazing technique that gives a painting a jewel-like quality.
History
According to Creevy the glazing technique dates back to at least the 15th century and is the oldest known form of oil painting. At first, the technique was only used to unify the strokes of an egg tempera underpainting. Rembrandt's paintings exemplify this technique perfectly, says Creevy.
Grisaille
To use glazing successfully, masters such as Vermeer would have created a grisaille---from gris, gray in French--an opaque underpainting using mainly black, white and gray paints. (Underpaintings can be made using a variety of colors, but the colors should be monochromatic.) A good way to understand an underpainting is to think of a color photo that has been converted to a black and white photo in a computer program. After the photo has been lightened several shades, what's left would be akin to the underpainting. A first layer of glazed transparent paint would be applied and left to dry. Another glazed color would be applied next. The process would be repeated until the desired color has been achieved.
Transparent Versus Opaque Paints
The glaze itself is made when a small portion of paint is added to an oil or alkyd, the effect of which is transparency. The glazed layers must be transparent--albeit colored--because the layers underneath them must show through. Some colors, such as lead or titanium whites, can never be transparent and thus can never be used for glazing purposes. That is not to say that they cannot be used in a painting in which the artist chooses to glaze part of the project. In fact, master artists like Vermeer used an opaque underpainting which was then covered by transparent, glazed layers to add depth and to create colors that were not available during his time. Using the glazing technique, the painter would optically blend two or more layers of paint, thus creating a new shade.
Glazing Mediums
For the beginner, the best bet might be to buy an already prepared glazing medium---a walnut alkyd, for example. For the more adventurous type, a mix of sun-thickened linseed oil and Venice turpentine produces a nice high-gloss glaze. Additionally, artist Margaret Krug warns in her book, "An Artist's Handbook," that linseed oil tends to yellow more quickly over time than a medium like poppy seed oil. This will change the look of the piece over time. That being the case, as with all new artistic techniques, it's best to experiment to determine what works best.
