Day 11 — Alkyds: Modified Oils, Faster Drying, and Modern Studio Tradeoffs

Alkyds: Modified Oils, Faster Drying, and Modern Studio Tradeoffs

Day 11 – The Chemistry of Binding Agents Masterclass

Alkyd revolution: Alkyd resins transformed painting workflows in the 20th century, allowing artists to harness the best of oil and synthetic chemistry in the studio.

In 1949, the American painter Thomas Hart Benton completed his dynamic mural "America Today": a kinetic vision rendered with an oil technique, yet not wholly bound by the sluggish pace of linseed. In his notes, Benton enthused about “quick drying grounds”—a revelation for muralists and illustrators alike. Behind this acceleration, a chemical revolution was quietly taking place. By the late 1930s, alkyd resins—engineered from natural oils and alcohols—were entering artists’ studios, promising the luminosity of oils with the speed and flexibility demanded by modern art production (Tate, 2018; Getty Conservation, 2006).

The Chemistry of Alkyds

Alkyd synthesis: Schematic illustrating the key chemical building blocks of alkyds—oil, alcohol/polyol, and acid anhydride—reacted to form an oil-modified polyester binder (Getty Conservation Institute, 2016).

Alkyd resins are oil-modified polyesters created by polymerizing drying oils (like linseed, soybean, or even safflower) with polyols (such as glycerol or pentaerythritol) and dicarboxylic acids/anhydrides (most commonly phthalic anhydride). This process yields a robust, flexible, and quickly oxidizing polymer film, ideal for paint binders (Eastaugh et al., 2008).
Unlike straight oils, alkyds have a three-dimensional structure that allows oxygen to penetrate and cure the film far more rapidly than classic oil, while retaining oil’s pigment-wetting power and surface clarity.

Short History and Famous Uses

The first alkyds were developed for industrial coatings and adopted by artists by the 1940s. Manufacturers like Winsor & Newton and Grumbacher began producing alkyd mediums in the 1960s. David Hockney famously painted with alkyds to exploit their quick-drying qualities for his layered pools. In conservation analysis, alkyd films are now regularly detected in works by twentieth-century realists and muralists (Tate, 2018; National Gallery Technical Bulletin, 1985).

Conservation insight: Alkyd paintings show fewer yellowing issues than many traditional oils, but their long-term conservation is still an evolving topic; many labs have successfully cleaned alkyd paintings that had been mistakenly categorized as oil (Getty Conservation Institute, 2016).

Alkyds vs. Traditional Oil: Pros & Cons

Alkyd vs. oil: Alkyd mediums excel at speed and are robust but require workflow adaptation and conservative use if traditional effects or long-term flexibility are priorities.

Practical Studio Workflow

Workflow tips: Alkyd mediums can radically speed up your layering. Slow down cure by adding more oil or using closed palettes; speed it up with moderate warmth and air circulation.

• For underpainting and rapid glazing: mix alkyd medium (such as Winsor & Newton Liquin, Gamblin Galkyd) at up to 1:3 ratio with oil paint.
• For alla prima: use sparingly for an oil-like open time but expect setting within a single session.
• Layering: Alkyd-based paint dries to the touch in 3–8 hours (vs. days for oil), so multiple glazes can be applied in one day.
• Tip for slowing drying: Work cooler and keep containers tightly closed; alkyd’s cure rate increases with oxygen and warmth (Gamblin, 2022).
• Final varnish wait: Allow 2–4 weeks for full curing before varnishing if paint was heavily modified with alkyds (Winsor & Newton, 2023).

Best Uses and Contemporary Applications

Alkyds excel for illustrators, muralists, plein air painters, fast underpainting, and any workflow requiring rapid paint build-up. They are increasingly used as conservators’ fill/retouch materials because of rapid set and flexibility (Getty Conservation Institute, 2016). For hyperrealist layering, alkyds are a favorite base.

Conservation, Lab Insights, and Longevity

Alkyds show very good chemical resistance to solvents and environmental pollutants, with greater flexibility than many synthetic resins. However, long-term aging data show moderate embrittlement risk if alkyds are applied too thickly or are aged at high temperatures (Croll, 2008; Tate, 2018). Conservation studies note generally favorable yellowing profile and cleaning response (Getty Conservation, 2016).

Key Takeaways

• Alkyds are a 20th-century synthetic binder derived from drying oils, offering the fast drying, high pigment load, and flexible film favored by modern painters.
• Studio advantage: Enables rapid, layered painting sessions with less yellowing than oil.
• Some tradeoff with blending/open time and potential ageing concerns in very thick films.
• Conservation evidence supports alkyd’s durability for most studio applications, but best results come from thin, layered use.

Sources

• Tate. The Use of Alkyd Binders in Twentieth-Century Art.
• Getty Conservation Institute. Alkyds and Conservation.
• National Gallery Technical Bulletin 34.
• Gamblin. Alkyd Resin: The Oil of the Future?
• Winsor & Newton. Safe Use of Alkyd Mediums.
• Eastaugh, N., et al. (2008). Pigment Compendium. Elsevier.
• Croll, S.G. (2008). "Alkyd Resin Chemistry, Structure, and Mechanical Properties." Progress in Organic Coatings.