Term: Oiling Out

Oiling out is the process of applying a thin coat of oil medium to an oil painting which has sunk in or become dry. The oil can be applied to the entire painting or just to the area that needs to be enlivened. To be absorbed properly the medium must remain on the surface for at least two minutes. A painting may require more than one oiling out depending on how much the painting has sunk.

Oiling out can be one of the last steps in the painting process, or it can be done before painting another layer of paint. The thin layer of oil makes the paint surface more receptive to new paint, so that the newly applied paint will look like it was applied when the other paint was still wet. Without oiling out, newly applied paint goes on dry and must be scumbled to be blended with the old paint.

Here is a quote from Harold Speed describing how to oil-out a painting:

"I have found that the best method of doing this is to apply with a large brush, not very full, a mixture of equal parts of poppy oil, turpentine or petroleum, and water, shaken up together. The water helps it to bite on the surface and cover more easily, and if left for a short time the small quantity will evaporate with the turpentine, leaving the thinnest film of oil. Any surplus should be wiped off with the palm of the hand and only enough be left on to bring up the colour."