Winsor and Newton - Linseed Oil - 75ml -Artisan Water Mixable Linseed Oil is the main binder in the Artisan colours. When mixed with colour it reduces consistency. Linseed oil is the most commonly used medium. It is combined with water or Thinner to maintain the structure of the paint film. It is also used when painting in layers to maintain the fat over lean rule: each successive layer must have more oil in it than the previous one.