Summer Marsh 8"x10" oil with knife
There are three basic ways to paint in oils solvent free, or at least with minimal use of solvents. The first is to use Gamblin's range of solvent free mediums and safflower oil for brush washing to minimize the use of solvents. There are limitations to how one can paint with this approach, which doesn't allow thin washes of paint in the under layers.
Lapstrake Dinghy 9"x12" oil with knife
The second approach is to use water mixable oil paints. Several paint companies make this type of paint, which is regular oil paint with an added emulsifier, so that the brushes can be cleaned up with water. Some dilution with water is also possible, but in my experience with this these paints, using the paint maker's medium is the best way to thin them. I've used the Windsor & Newton water mixable oil paint, which took a little getting used to. I found the result to look just a bit shinier than my paintings done with regular oils, and they did take longer to dry. All totally solvent free.
Low Tide at Tidewater oil with knife on treated paper
But there is another way to paint without solvents, and this one is my favorite. Painting with a knife doesn't require thinning the paint, and to clean a knife, you only have to wipe it off with a rag or paper towel. I love the look of knife paintings, and once you get used to it, it's a faster way to paint than with a brush, because so little time is needed to switch between colors. For me, the technique is somewhat different than using regular oil paint, because layering the paint is easier with a knife. So for example, clouds can be painted on top of the sky, where I would normally paint the clouds before the blue part of the sky. I also paint with a knife with the panel horizontal rather than almost vertical, to aid in turning the painting around, which is convenient when painting with a knife.
In my new studio, I haven't quite gotten the ventilation sorted out, so knife painting is a nice option.
Bobbi - Painter. Sketcher. Teacher. Boat and Dog Lover.