Since 2007 photographer Matthias Schaller has photographed raw, abstract paintings. The paintings however are not found on canvas, but rather smeared onto the tools used to craft each work of art—the palettes. His series, Das Meisterstück (The Masterpiece), claims these behind-the-scene objects as portraits of the artist, while also giving a direct insight into the detailed techniques performed by each painter. (You can read the rest of the article on This IS Colossal here).
I usually use various food containers as palettes (here's several that used to house shiitake mushrooms from Trader Joe's).
I wonder how my palettes stand up? It never occurred to me to save them. I used to flatten out beer carriers to use, and they had a handy handle. I've felt guilty because I don't use glass and then scrape it clean , like I thought you're "supposed" to do.