I found out this trick to clean up dirty oil paint palette by accident. One time I left a puddle of acrylic paint in a tray and forgot it. The next day when I peeled off dry acrylic paint film, it lifted the old oil paint residue on palette beautifully. I tried several times and noticed that the acrylic paint was better to have some thickness. So, to clean up the dirty oil paint residue on color palette, you need acrylic paint. I use Utrecht Artists’ Acrylic Paint. It says heavy body on the tube. I believe any thick acrylic paint will do. Choose the color you barely use and squeeze a lot paint onto palette directly. Then use a palette knife to spread the paint. Make an even layer with some thickness but not too thick. Otherwise it takes forever to dry up. Next, let it dry completely. At last, you can peel of acrylic paint film slowly and enjoy the result.
My palette is glass surface and this method works great. The plastic surface works too. I am not sure about wood. You may expect a few spots of paint residue staying behind. You can either repeat this method again or use a palette knife to clean up the leftover.
Here I have some snapshots during the process. I use black and burn sienna acrylic paint so you can see the color block on the film. But everything else on the paint film is from the dirty palette underneath. Those are old oil paint residue. When peel off the dry acrylic paint film, please be patient and do it gently and slowly. You want it to lift as much residue as possible. Try to maintain the film in one piece.
Now, you can enjoy a fresh looking color palette~! I still have some acrylic paint spots here but the glass surface is clear and reflective.
PS, please ignore the dirty frame. I haven’t cleaned up that part yet. 😀
I hope you find this post helpful.