Raw and cooked linen oil
Raw and cooked linen oil are two different forms of linseed oil, which is derived from flaxseed. The main difference between the two lies in the processing method and the resulting properties of the oil.
Raw linen oil, also known as raw linseed oil, is extracted from flaxseed through a process of pressing. It is a natural, unrefined oil that retains its original characteristics and composition. Raw linen oil has a pale yellow color and a relatively thick consistency. It dries slowly when exposed to air, forming a tough and durable film. This slow drying time makes it suitable for artists who prefer extended working periods, allowing for more flexibility in blending and manipulating colors.
Cooked linen oil, on the other hand, is raw linen oil that has undergone a heating process called "boiling." During this process, the oil is heated to a specific temperature to promote polymerization and oxidation. This alters the chemical structure of the oil, resulting in a thicker and more viscous consistency compared to raw linen oil. Cooked linen oil has a darker color, ranging from amber to brown, and it dries faster than raw linen oil.
The primary purpose of cooking linen oil is to enhance its drying properties. The heat causes the oil molecules to react and form cross-links, leading to faster polymerization and drying. This makes cooked linen oil more suitable for artists who desire quicker drying times in their paintings.
In terms of artistic application, raw linen oil is often preferred by artists who work with traditional oil painting techniques. Its slow drying nature allows for extended manipulation and blending of colors on the canvas. Cooked linen oil, on the other hand, is commonly used in mediums or varnishes where faster drying times are desired.
Both raw and cooked linen oil have their respective advantages and uses in the artistic realm. The choice between the two depends on the specific needs and preferences of the artist, including the desired drying time, consistency, and handling characteristics in their creative process.