hi, i have this painting and i am unsure if it's an oil painting or something else? it appears to be very old judging from the back side but it isn't on canvas. it is on a piece of tile/particle board or something so i'm confused. it is pretty worn and dingy looking because there isnt a piece of glass covering it. it appears to have texture like an oil painting though. the signature is (Percival) Rosseau and is dated under the signature 1928 i think. can anyone tell me anything about it or know where i can find answers?