Oil Painting - It's Complicated

 Glazing is no longer a common process, what happened? In "Glazing" by Michael Wilcox he states that Impressionism, prevelent in the late 1800s, and the desire to capture "fleeting eccentricities of light" brought about the change.

How does glazing differ? Thin layers of transparent colors are applied to the surface that allow the color beneath to show through, this creates the mix of colors. Instead of actually mixing the colors on a palette and applying them to the panel as would be done post impressionist.

"Alla Prima" roughly translated as "all at once" refers to applying paint wet-into-wet is also a period technique.  Alla prima is the standard application of oil paint taught today.


During period glazing was often used for principal figures in the painting, usually rendered by the master, while alla prima was used for unimportant beground images that were often rendered by apprentices.

Benefits of Glazing:

1. Glazing allowed artists to create colors when a pigment was not available.
2. Glazing provides a depth and intensity not found in other methods.

Benefits of Alla prima:

1. Alla prima allows for speed.
2. Alla prima is often opaque.

The cold weather in Northern Europe benefited oil painters as glazing layers dried more efficiently. Violets and bright orange pigments were absent in the palette and could be created through glazing; i.e. red thinly layered over blue would create a violet creating colors otherwise not available.

Panel Preparation

Preparation of the panel and the general approach to initiating the painting altered little from those for egg tempera, especially in the early years of oil painting. 

Underpainting

Underpainting allows for the establishment of the composition, solidification of perspective and the value range of the painting. The cartoon, or study, is refined further by the underpainting, particularly value. Jan van Eyck used egg tempera for the underpainting working on wooden panels. This process was later adopted by Venetian painters.

Underpainting varied by school and artist.

Priming of the panel by washing a base color on the surface and wiping it off evenly is called imprimatura. Imprimatura is done for effect by different artists or schools.

Grisaille is also known as "dead color" is the term derived from the French word "gris" meaning grey. Greys are mixed with black and white to draw in the subject, forming the value range for each element. Greys could be created by combining blue with burnt umber with white (usually lead white). Remember when working with pigments, mixed or powdered to take appropriate precautions. Lead white is toxic and carcinogenic that is absorbed through the skin.

Verdaille uses opague greys or green greys for the understudy, and was used by Titian.

If a brown is used to create the understudy it is referred to as brunaille.

Terra verte, a grey green earth pigment, can be used for the underpainting and is referred to as verdaccio. Verdaccio was used beneath areas of flesh to aid in creating flesh tones even beneath egg tempera. Difficult to replicate today as the best deposits of terra verte have long since been exhausted. It can be replicated by mixing cerulean blue, hansa yellow then dulling the color with cadmium red light. This process was updated by 1500s. This color and technique can be seen in the "Manchester Madonna" by Michaelangelo.

Application of Color

Glazing consists of layers of transparent paint, often of different colors. A strong understanding of color and the color wheel is very beneficial when using this technique. The light penetrates each layer as if it were created in glass reflecting each layer back to the eye. The effect is a deeper and richer painting that cannot be replicated by other techniques.

In his book, Wilcox also suggests that brocades were rendered by applying the painting layer then removing the pattern of the fabric brocade with a wooden or ivory tool. This technique would not perform well using other painting techniques.