Exploring Glazing in Oil Paintings
One of the advantages of painting in oil is that you can work in layers of color. The big overall term for this technique is glazing, in which you can see two distinct colors at the same time.
In the following sections, you can explore some interesting properties of oil paint. Because oil painting owes a lot of its knowledge to the Renaissance artists, you get to discover some fancy Italian painting terms, as well.
Bringing out the undertones: Imprimatura
Imprimatura refers to starting with a colored surface instead of a white ground. Use it to establish the undertones. To achieve imprimatura with a pre-made canvas, stain it with a fast-drying coat of paint. You can leave a uniform field of color or wipe some color off in a pattern for your initial drawing of your image. Allow the paint to dry just a little bit, and then take a rag or a clean, dry paintbrush and wipe away some of the paint to establish the light areas of your image. Let it dry completely before continuing with the painting.
Scumbling and sgraffito
Scumbling is a thin or transparent layer of paint that's rubbed or scraped off. Start with an area of your painting that's dry and apply a thin, wet layer of oil paint. Then rub or scrape off enough so that only a residue is left behind. This technique works well with opaque colors, especially a light color over a dark color.
Sgraffito is similar to scumbling, but you scratch off the paint to make definite marks, lines, or textures.
Trying the dry brush technique
Dry brush is the application of a stiff, dried paint with a dry brush on a dry surface. The effect is small specks of paint that stand up on the surface.
Use a light touch and a stiff, dry brush as you drag the brush over the painting. Hold the brush at a shallow angle in relation to the canvas. The paint sticks only to the parts of the painting that are prominent. A rough-textured surface is more effective than a smooth canvas, and it produces more specks. This technique works best when applied with a slightly hard brush over a textured surface.
Adding texture with impasto
Impasto is painting with thick paint to add texture to an image. You can apply impasto with a painting knife or with brushes. Use the paint right out of the tube or make it heavier and stiffer by adding purchased impasto mediums to the paint. You can also dry the oil paint before application by first mixing the approximate color that you want to use and then leaving the paint to sit until it becomes firmer. After an hour or two, transfer the paint to your palette and apply it with a brush or a knife to the canvas.
Impasto painting sticks up above the surface and adds dimension to the painting. It creates an expressive and fragmented dramatic quality in the work.