I looted a painting "Velothi Triptych, Volcano" from a safebox in Gnisis, Vvardenfell. Whenever I try to launder it at any fence in Morrowind or elsewhere in Tamrie, I get a message it can't be laundered, even if I had not laundered any other items during the daily reset. I don't know if this is the case with other stole paintings, but so far this at least renders this painting completely useless for furnishing as it can't be interacted with.
The devil's in the details.