I'm taking an oil painting class on Monday morning. We work in water-soluble oils. Being that I never work in oil paint for real, I have a lot of technical aspects to learn.
This morning we used a glazing medium. Starting with an acrylic painting in grey tones, we "watered" down the oil paints to a wash consistency and gave the painting a wash of color. The thin oil paint tinted the already shadowed areas and gave it depth without all the work.
(acrylic grey tones)
(finished oil painting)