Re: Artisan Painting Medium
If it smells rancid I would not use it.
It is important to learn how to look up information online pertaining to ingredients and warnings. In this case, WN should be on the label. The information below is on the WN website.
Artisan Painting Medium is a stand oil based medium, ready-made from the bottle. This medium thins the consistency of Artisan oil colours and helps if your work involves creating fine details. It also improves the flow and wetting of the colour. It dries slowly to a flexible film and is good for "oiling out". Oiling out is the application of an oil medium to a painting which has sunk or lost its oil to the layer underneath.