Paint thinner works well on oil-based paints and varnishes, but using it on the wrong materials can cause damage.

While you should be able to easily clean most wall art and decor in your home, if you have an oil painting, a family heirloom or a vintage piece of art that needs more attention or needs restored ...

My grandfather was a heavy smoker. -- Karen G., Santa Fe, New Mexico Karen, you can find a product called a painting restorer for cleaning old paintings. Many art supply stores carry it.