Paint, dried in tubes. I'm about out of both cobalt blue and raw sienna, so I slit both tubes to rescue the bit of paint there. There was more of the blue... I wetted it and scraped, brushed what I could into white bowls. For all the work, it may not have been worth it. I did get enough R Sienna to finish my study, and there's enough blue to do another one. I don't think the quality was as good as it was originally. Most of the tubes I have (a lot) are dried so many will just get tossed unless there's enough to do the work. (these are preliminary studies)
My tip here: may not be worth the work to rescue paint from dried WC tubes.
My tip here: may not be worth the work to rescue paint from dried WC tubes.