From raw cold-pressed to heat-bodied stand oil, a practical breakdown of what each oil does, how it ages, and when to use it.
Every oil painting is, at its most fundamental level, pigment suspended in a drying oil. That oil is not merely a vehicle for application. It becomes the paint film itself, polymerizing into the flexible, durable matrix that binds your pigments for generations. Choosing the wrong oil for the wrong situation compromises everything above it.
The good news is that once you understand how drying oils actually work, the choices become straightforward.
Unlike watercolors or acrylics, oil paint does not dry by evaporation. It undergoes autoxidation: oxygen molecules from the air insert themselves into the carbon-hydrogen bonds of the oil's unsaturated fatty acids, forming hydroperoxides. These then cross-link with neighboring fatty acid chains, building a polymer network that forms the tough, somewhat elastic film we recognize as dried oil paint.
The speed and quality of this process depend directly on the fatty acid composition of the oil. Oils high in polyunsaturated fatty acids (particularly alpha-linolenic acid) dry faster and form harder films. Oils high in monounsaturated oleic acid dry more slowly. This is measured by an oil's iodine number: oils above 130 are true drying oils, 115 to 130 are semi-drying, and below 115 are non-drying (never suitable for paint).
The workhorse of oil painting. Linseed is high in alpha-linolenic acid, giving it a high iodine number and fast drying relative to other artists' oils. It produces a durable, hard film with excellent adhesion.
Caution: Linseed oil yellows more than walnut or poppy over time, making it less suitable for cool blues, whites, and pale flesh tones.
Walnut oil is the preferred binder for pale, cool, and delicate colors. It yellows significantly less than linseed and produces a slightly less brittle film. The trade-off is a marginally slower drying time. Rublev Colours Walnut Oil is alkali-refined for maximum clarity and consistency. Use walnut oil for your whites, blues, and any passages where color fidelity over centuries matters more than rapid drying.
Poppy oil dries the slowest of the commonly used artists' oils and yellows the least. It is sometimes used in pale, wet-into-wet alla prima work where extended open time is an advantage. However, its slow cure and lower film strength make it unsuitable for underlayers or any technique that requires building multiple sessions.
Stand oil is linseed oil that has been heat-polymerized under vacuum or inert gas, producing a thick, honey-like oil with a slightly elevated refractive index (~1.49 vs. ~1.48 for raw linseed). This matters for glazing: the closer the RI of the binder matches that of the pigment, the more transparent the paint film becomes.
Stand oil dries to an enamel-like, nearly brushstroke-free surface with excellent leveling. It also yellows less than raw linseed because thermal polymerization partially completes the oxidation process, leaving less reactive material to yellow further. Use it diluted. Pure stand oil is very thick and dries slowly. A small addition (10 to 20% by volume) to a refined oil medium adds flow and gloss without significantly delaying curing.
Warning: Adding large amounts of bodied oil increases the risk of paint film wrinkling as the skin forms faster than the interior can cure.
With over 1,300 hand-mixed pigment recipes, Artist Studio Pro helps you find accurate color matches using the pigments you actually own. Use the Studio Log to record the oils and mediums you pair with each pigment, building a personal reference for fat-over-lean decisions across your practice.
Choose your oil based on the color, layer position, and drying time you need. Alkali-refined linseed is the most reliable all-purpose binder.