For years I avoided oil painting because I never liked the fumes of solvents, such as turpentine and mineral spirits, which are commonly used to thin paint and wash brushes. There is such a thing as odorless mineral spirits (OMS), but it still smells, only not as much. And though OMS is said to be less toxic, it’s still toxic.
I’ve painted with watercolors and acrylics, which don’t require the use of toxic solvents — all you need is water or an acrylic medium. But you can’t use these things with oils, so I thought I’d never paint with oils. Then I heard of a way to use oils without the use of toxic solvents.
Before I go any further, I should point out that in oil painting there’s a rule called “fat over lean” which has to do with how fast or slow each layer of paint dries. When the paint is overlaid with one or more layers, the under layers need to dry first. Otherwise, the outer layers might crack. And since oil prolongs the drying time of a layer, it’s best if the under layers are thinned without additional oil. Thus, the use of a solvent to thin the paint for the under layers, and an oil medium to thin the paint for the outer layers.
An oil medium doesn’t just thin the paint. It also helps colors to blend well when mixing on a palette, and gives the paint a creamier feel for a smoother application. Linseed oil is a popular medium, but it has a tendency to yellow over time. Stand oil is a thicker linseed oil that doesn’t yellow. It’s often mixed with turpentine for use as a medium. Since I don’t want yellowing , and I avoid turpentine, I use walnut oil. It takes longer to dry than some oil mediums, but I’m okay with that.
To make a painting, I first prime the canvas with a thin layer of gesso, which helps the oil paint adhere to the surface. The next day I tone the canvas. To do so, I use a bristle brush to scrub a little paint into the canvas — a technique known as scumbling. Either that or I use acrylic paint to tone the canvas. You can paint oils over acrylics, but never acrylic over oils. If you try, your painting will eventually crack and chip. Next I paint some structural lines and tonal values — often referred to as an underpainting. Sometimes I paint in layers. I don’t mix any medium into my oil paints until I get to my final layers. And I try not to make a lot of layers. In fact, sometimes I paint alla prima — an Italian word and art term meaning at first attempt. With this method, wet paint is applied to previously applied wet paint, without having to wait for the layers of paint to dry.
As for washing my oil painting brushes, I just use straight walnut oil to clean my brushes in-between color changes while painting, and a brush wash when I’m done painting. I make my own brush wash, without using turpentine or mineral spirits. Here’s how I make it:
What’s Needed:
- Large jar with lid
- 1/2 cup olive oil
- 1/2 cup Murphy Oil Soap
- 1/2 cup water
- Round nylon dish scrubber
Instructions:
- Pour the olive oil, Murphy Oil Soap, and water into the jar. Drop in the dish scrubber.
- Secure the jar with a tight fitting lid and shake to mix. Remove lid. If the scrubber floats, push it down with a paint brush.
- Wipe a used brush on a paper towel to remove most of the paint.
- Swish the brush around in the jar, and rub the brush hairs on the scrubber to help loosen any stuck-on paint, then wipe again.
- If done painting, dip clean brushes in a little walnut oil, then wipe one last time.
- Lay brushes flat to dry. After they dry, store upright.
Olive oil and water are safe, and Murphy Oil Soap contains 98% naturally-derived ingredients, so I can feel better about the way I clean my brushes. Still, it’s a good idea to work with the windows open or outdoors, since there’s a small percentage of ingredients in Murphy Oil Soap that may be of “moderate concern,” according to the Environmental Working Group (EWG), which is a non-profit, non-partisan organization dedicated to protecting human health and the environment.