Applying oil paint in translucent layers is known as “glazing” – this is a great technique for the artist who wishes to explore painting techniques other than “alla prima”. An oil paint glaze is a layer of oil paint that is “see-through” or translucent and which will modify the hue of the paint beneath. For instance, a bright red object will appear more subdued if a thin layer of blue or brown is applied on top. In the pictures below we tried all kinds of transparent oil paints on top of different colours.
What is the purpose of glazing when using oil paint?
Glazing is a technique that has been employed by painters since the invention of oil painting. In the simplest terms, glazing consists of brushing transparent layers of paint over another thoroughly dried layer of opaque paint. The two layers of paint are not physically but optically mixed.
The paint used to glaze must be diluted by a medium to achieve the correct fluidity for brushing. Glazing creates a unique “shine through” stained glass effect that is not obtainable by the direct mixture of paint.
“Dead Colouring” or Underpainting is the first step.
Rembrandt’s underpainting with thick lead white “hoogsel” (under layer impasto)
An underpainting is a monochrome version of the final painting intended to initially fix the composition, give volume and substance to the forms, and distribute darks and lights in order to create the effect of illumination. The lack of colour probably explains the word “dead” in the term “dead painting.” This method is used to show only your value (dark and light).
- Grisaille (a monochrome Ivory black and Flake White underpainting)
- Verdaccio (green underpainting—a Mars Black, Yellow Ochre and Titanium or Flake White mix, some painters use Chrome Oxide green). The green can also “kill” some of the intensity of pure orange and pick flesh tones, which can otherwise look to plastic or doll-like on a painting.
I use it because it’s an easier way to search for a good composition, you don’t need to change the colours only the light and dark.
After the underpainting is thoroughly dry you can apply colour. Under paintings were usually executed in warm earth tones on neutral gray backgrounds. Raw Umber at times is mixed with a black and is frequently used for this purpose.
Five reasons to glaze
Mars black is the most neutral black, not warm, not cool
- One—artists previously had few of the brilliant colours available to us today. Strong purples and oranges were not always easy to come by. Purple had to be made by glazing blue over a reddish underpainting or vice versa.
- Two—glazing creates an extraordinary luminosity impossible to achieve otherwise. In order to appreciate this effect, one has to view the painting directly for no reproduction can convey its jewel-like quality. Only very transparent paints are suited for glazing.
- Three—if the colours in your painting are too bright and too separate from each other with glazing you can bring them together.
- Four—bright colour pigments are the most expensive colours, so for trying to find your composition is cheaper to work in greys and earth colours.
- Five—Rembrandt and Rubens, in particular, are known to have used underpaintings very effectively. It is believed that artists once kept a number of underpaintings in their studio waiting for clients’ interest before completing the painting with full colour and detail. A lot of time you can still see the underpainting in the background of the painting, where the paint is thin.
Only transparent pigments are used for glazing: (check if your brand is transparent)
The opacity of a pigment depends largely on the size of the pigment, the concentration of pigment in the binding medium and some pigments reflect more light
- Madder Lake (Alizarin, Quinacridon, Scarlet)
- Burned Umber
- Burned Siena
- Ultramarine blue
- Yellow lakes
- Burned Carmine
- Sap green
These are the pure pigments, brands make mixes from these pigments, Scheveningen has a beautiful range of transparent.
*Note – Zinc White is the most transparent white but don’t use it for glazing—its more for scumbling (see below). Zinc White from Winston & Newton is not transparent.