As an artist who is very sensitive to the traditional solvents used in oil painting, I have been searching for an alternative for a number of years. The first replacement I tried was acrylics, specifically Liquitex Heavy Body acrylics. They work great but I have a lot of difficulty matching colors precisely with them because of the color shift. I learned a lot of special techniques for using them from Jerry Yarnell that work great for blending, etc, but the color shift when drying still gives me a lot of trouble.
My next alternative was to try using water soluble oils. While water works nicely for cleaning brushes and general cleanup, I quickly found that trying to thin them with water results in a gummy mess as the water evaporates. I had to either use water soluble linseed oil or odorless mineral spirits for thinning. This helped a lot because it limited my exposure to the OMS since I didn’t need it for brush cleaning. Even with this limited use, in a prolonged painting session or in a classroom environment, I would end up with a roaring headache!
Recently, I discovered Art Treehouse and their Bio Based Artist’s Thinner and it’s the perfect solution! It is actually a stronger solvent than OMS and is certainly less-toxic! As a retired engineer, it is second nature for me to research anything I am interested in and before I purchased the “Bio-Thinner” (I just now made that nickname up!), I thoroughly researched it to find out exactly what it could do. It’s soy based and quite safe
I sometimes make my own paints and mediums from scratch and will be making up some mediums with it soon. I expect it to work well since, as a thinner for my paints and for cleaning my brushes, it’s working perfectly so far!
The only potential drawback to it is that it has a slight odor which some might not like. To me, it seems to be a blend of licorice and vanilla aroma that I find pleasant. If the aroma is a problem, it is easy enough to keep it in a covered wash cup when you are not actively using it as with the OMS.
By the way, it works great as a thinner for my water soluble oils, so I’ll be able to use them up!
For me, the “Bio-Thinner” is the perfect solution to my search for a less-toxic oil painting system!