Oil pastels (OPs) are my main painting medium, but there are times when I want to block in shapes and colors as a foundation to the painting before I start layering in OPs. So I will do what’s called a underpainting (using soft pastel) and then wash over it with alcohol. I like the effects and benefits that this technique offers. For instance I can make heavier/bolder colors without using the surface tooth, can create texture and if I don’t like the direction the underpainting is taking, I can remove the soft pastel and start over before it’s washed and set with alcohol (alcohol seals in soft pastel so the soft pastel dust doesn’t smear into the oil pastel as it is layered in).
The painting below, SeaBreeze, was painted with Oil Pastels that started out with a simple soft pastel underpainting and alcohol wash.
Instructions for using this process. I picked up this underpainting technique an artist did for an artist online community I belong too – it was shown as using soft pastel as both the underpainting and main medium. I figured the technique would work with oil pastels if hardboard, artist canvas board, or pastel board were used as the painting surface. If the surface can handle a wet wash then it should be able to take an alcohol wash – I found this to be true.
(btw, the alcohol is an antiseptic that can be found at a pharmacy [it’s not the kind that you drink]. Once applied the alcohol dries/evaporates very quickly)
Preparing Painting Surface and Applying Soft Pastel: I prepare my painting boards, here is the process. The surface is sanded then two coats of gesso and one coat of clear gesso are applied – let each layer of gesso dry completely before applying the next. The scene is then sketched onto the surface. It’s at this point that I block in each subject laying down a thin layer of soft pastels (take extra precaution not to apply the soft pastel too heavily, because the alcohol will darken the color).
(The main reason I like using the alcohol wash, it dries over the soft pastel and the pastel dust doesn’t mix into the oil pastel when I begin to lay the OP down. After the alcohol wash dries I can rub my hand over the painting and not take up any soft pastel dust.)
The Alcohol Wash Process: Using a brush and alcohol wash the entire soft pastel area, being careful not to merge lines or smudge colors together. The brush is a great tool, because patterns can be scrubbed in. For instance if I’m laying a foundation for rocks/boulders certain patterns will emerge that will aid me when I begin putting down oil pastels layers. By repeatedly going over the soft pastel when the alcohol is nearly dry the soft pastel can be lifted right off leaving the hardboard white, in other word creating different tones of the originally applied color. Once the alcohol wash dries, use a sponge roller to re-apply a coat of clear gesso for added surface texture.
SeaBreeze Through the Underpainting/Painting Process:
First, the soft pastel underpainting and alcohol wash:
Second, initial stages of layering in oil pastels: