Oil painting art reproduction gets its name because it is oil painting that is intended to be painted over in a scheme of working in layer. There is a popular misconception that oil painting art reproduction should be monochromatic, perhaps in gray-scales. In fact, a multi-color oil painting art reproduction is much more useful and was used extensively by oil painting art reproduction artists such as Giotto (whose oil painting art reproduction techinque is described in detail by Cennino Cennini).
The colors of the oil painting art reproduction can be optically mingled with the subsequent oil painting art reproduction, without the danger of the oil painting art reproduction colors physically blending and becoming muddy. If oil painting art reproduction is done properly, it facilitates over painting. If it seems that if one has to fight to obscure the oil painting art reproduction, it is a sign that it was not done properly.