This sketch copy I did of the top part of Renoir’s Dance at Bougival was done with oil on cardboard.
There was very little drawing done with the brush. The forms were built by brushstrokes of one color against another. This is an adaptation of the drawing stage that many art students will use if they are following a more rigid step by step procedure of completing a painting.
The cardboard soaks in the oil giving a more pastel like quality to the paint – making muddy color less likely.
There was also not that much mixing on the palette itself. This would keep the colors fresher and lively.