What can I expect an oil painting on untreated watercolour paper to do over time?

I liked the way the oil paint partially was absorbed into the paper.I got a kind of mat finish which I liked.I 'm worried about mold or paper deterioration.What can I expect an oil painting on untreated watercolour paper to do over time?
Over time I think you can expect the oil to soak through the back of the paper making it dark and greasy, and the paint on the surface to flake and crack. Mould is a distinct possibility.





Perhaps you could create a similar effect to the one you like by using a medium other than oils, such as artists' acrylic paint. It's possible to buy additives for acrylics which alter the consistency and finish, allowing you much more freedom to experiment.What can I expect an oil painting on untreated watercolour paper to do over time?
I have not heard of anyone doing that before. Watercolor paper probably isn't heavy enough for oil paint. Don't surprised if it flakes off or gets damaged when it's touched.
DO not expect so much. 15 years ago I used to print oil paints aplied on something like cardboard to skatching paper. I still have it today, nothing changed in appearance or hue.
The paper may deteriorate over time. When you use oil paint, it's best to prime the surface that you're going to paint on, this can be done with Gesso (sold at art stores), or with a couple coats of regular acrylic paint. This will protect the surface so you won't have the oil paint being absorbed through the surface.