This post is the next in my series about glazing paint colors. Last time I went through glazing mixtures for the color green. This time, I will be talking about violet. But first, lets review glazing. Glazing is the optical mixing of the glazed layers with the underpainting. However, when paints are mixed on the palette and then applied to the underpainting, the mixing is physical, not optical. The results of optical mixing are quite different than those of physical mixing.The combination of the reflection and refraction of light in optical mixing provides the luminosity associated with glazing. Transparent colors, rather than opaque colors, need to be used for glazing. An opaque layer of paint over a white background will block out virtually all of the light so that it never bounces off the white surface. The light bounces back at the surface or bounces around between the particles of paint. A transparent paint lets the light shine through to the surface as it bounces back from the surface. As layers of transparent paint are layered over each other, they allow the light to bounce off the previous layers, thus achieving optical mixing of the colors. The brightest results from layers of transparent paints require a white background.
Think of each layer of thinly applied transparent paint as a color filter. For violet we will need blue filters and red filters. There are warm and cool shades of both red and blue. Ultramarine blue is a warm blue, and Cerulean blue and Pthalo blue are cool blues. Alizarin Crimson is a cool red, and Cadmium red light is a warm red. Please note that Cadmium red light is an opaque color, so it must be put down first as part of the underpainting. Ultramarine blue, a violet-blue is warm because the light hitting the pigment reflects blue, followed by violet, and then a lesser amount of green. Cerulean and Pthalo blues, both green-blues, reflect blue, followed by green, and then a lesser amount of violet. Please note that Cerulean light is an opaque color, so it must be put down first as part of the underpainting. Alizarin Crimson reflects red, followed by violet, with a lesser amount of orange. Quinacrodone violet can be used as a substitute for Alizarin Crimson, as Quin Violet is a violet-red. Cadmium red reflects red, followed by orange, with a lesser amount of violet.
To mix a bright violet through glazing, intermingle a viiolet-blue layer with a violet-red layer. Thus, intermingling Ultramarine blue layers with Alizarin Crimson layers produce a bright violet. Using Quin violet instead of Alizarin will result in a more blue violet. The end result will also vary depending on how many and how often layers of red and blue are glazed over each other. Experiment by laying down red first or blue first. Alternate layers of the blue and red, or lay down more blue or more red depending on whether you want more of a blue violet or red violet.
To dull the violet, use Cadmium red light instead of Quin violet or Alizarin because Cadmium red is a poor carrier of violet. Remember that Cad red is opaque, so it must go down first as part of the underpainting. Make it as bright as needed, as you will not be able to go over the blue again with the red. By applying very thin layers of the transparent Ultramarine blue the color can be taken from a mid intensity red-violet to a mid intensity violet and on to a mid intensity blue violet. For a more pastel look, try mixing the red with some white for a pink underpainting.
An alternative way to get a mid intensity violet is to use the violet-red with a green-blue, such as Cerulean. Remember that Cerulean is opaque, so it can only be put down once as the underpainting. Make the layer as bright as you need it to be, as you will not be able to layer more Cerulean on top of the Quin Violet or Alizarin. For a pastel look, add white to the Cerulean blue. Note that Pthalo blue, a transparent blue could be used instead of Cerulean. With Pthalo blue, you can have multiple layers of blue mixed in with the red layers.
To make a very subdued violet, mix two poor carriers of violet: a green-blue and an orange-red. Note that Cadmium red light and Cerulean blue cannot be used together to make a glaze because both are opaque. However, Phalo blue and Cadmium red can be used together as long as the Cadmium red is put down first as part of the underpainting, and the Pthalo blue layers are glazed over it.
The intensity of violet can also be controlled by adding its compliment, yellow. One method is to lay down an underpainting of Cadmium yellow light. Then glaze over it with alternate layers of Ultramarine blue and Quin violet. Try using Hansa yellow light as an alternative to Cadmium yellow light. You can also make a bright intensity violet from Ultrramarine blue and Quin violet, and then lay down layers of Hansa yellow, a semi-transparent paint, until the violet is dulled down to the intensity that you want. You can also try substituting Yellow Ochre for the opaque underpainted yellow for a different dulled violet.