I really love painting in oils. This one brings back fond memories of a fun week. ; Good drying time makes oils easy to manipulate. Alkyd oil is like a drier in oil paints. ; Look how I simplified the area behind the tree on the left, keeping it down to three basic concentric rings. the foreground, (ring 1) middle ground (ring 2) and background (ring 6). Here is something on driers.
Siccatives are metal salts soluble in oil. They speed the absorption of oxygen by the fatty oils, a two percent addition to paints is all that can safely be used. The addition of damar is a much safer practice, but that leaves you with two days drying time instead of one. Siccatives have been used for as long as mastic paints have been around, in the B/C era.
The first pigments, iron ore limonite, contained manganese siccatives. Green contained a copper resinate, sugar of lead was an early drier, it's called lead acetate. Today we use a cobalt oxide and limonite mix, to me the deep color purple is objectionable, and I would rather have the clear sugar of lead or the white calcinated stannum oxide, like the Egyptians used. Even white lead oxide could be heated and sponificated clear in oil and used as a drier.
There were mediums called malbutter, megilp, and Maroger made of heated oil, wax and lead in the past that worked very well. They added a buttery character to the paint and were very popular.
