For an oil painter, your medium is very important. You depend on it both to create different effects with paint, like thin glazes, and to protect the paint itself.
For years I used a traditional medium involving equal parts linseed oil, turpentine, and damar varnish, often with a few drops of cobalt drier. My studio in SF requires something less toxic, so I struggled for years to find something that worked as well but wouldn’t fume me out.
Sadly, at one point I mistakenly used some Turpenoid “natural” because, hey, it sounded…natural. It may be natural, but it never dries! It is fine as a brush cleaner, but for anything else, disaster. I believe in the small print somewhere it says not to use it as a medium, but I have no idea why they did not put this information in big letters on the front.
Thankfully I was able to discover my error pretty quickly, but this piece has been a recurrent victim of it, because after six years, it had areas that were still not dry. I store all of my paintings, once dry, in plastic. I waited for years to wrap this piece but when I recently took the plastic off, some paint came off with it.
After cursing a while, I decided to take the recent damage as an opportunity to rethink the piece. Perhaps its new name will be Lemonade.