Part 1 of 2 of the “Solvent‑Free Oil Painting Mediums” series
Why Artists Care About Solvent-Free Alkyd Mediums
Solvents accelerate drying and alter paint handling, yet they also introduce fire risks, VOC emissions, and health concerns. Consequently, many painters seek “solvent-free” alkyd gels and fluids that promise faster drying without the odor of mineral spirits or other solvents. But the label is not regulated, and its meaning shifts from brand to brand. This article clarifies the term, reviews current regulatory and marketing benchmarks, and compares leading products, enabling you to choose and use these media with confidence.
Defining “Solvent-Free” in Alkyd Mediums: Regulation vs. Marketing
Regulatory benchmarks
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U.S. EPA VOC limits – Architectural and consumer coatings must remain below 50–250 g/L⁻¹, depending on the category (U.S. EPA, 2025). A product may market itself as “zero-VOC” once it drops under 5 g/L⁻¹, but no federal rule defines “solvent-free.”
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ASTM D4236 – The art-materials labeling standard requires hazard statements when chronic health risks are identified; it does not quantify solvent content (ASTM International, 2016).
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ISO 14021 – Self-declared environmental claims, such as “solvent-free,” must be “truthful and not misleading”; trace amounts (background/trace levels) are acceptable if they are residual and not intentionally added (ISO, 2016).
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FTC “Green Guides” – “Free-of” claims must show no more than harmless trace levels and no substitute chemical that poses the same risk (FTC, 2021).
In short, regulators tolerate trace residues but expect marketers to qualify bold claims. Therefore, artists must read the Safety Data Sheet (SDS), not the front label.
Practical studio definition
Most conservation scientists and paint makers now treat a medium as solvent-free when
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No hydrocarbon is intentionally added, and
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the finished formulation contains ≤ 0.5 % VOC by weight.
How Alkyd Resins Are Made—and Why Solvents Appear
Alkyds are highly branched polyesters modified with drying oils. During manufacture, an aromatic solvent such as xylene is boiled with the resin to strip water from the reaction mix. That process solvent is later vacuum-stripped, yet laboratory tests still detect small residual amounts (often at low parts‑per‑thousand levels) (Solvent-Free Alkyds brief, §3). Consequently, “solvent-free” refers to the formulated medium: no mineral spirits are added later to adjust viscosity.
Strategies for Avoiding Added Solvent
Alkyd resins are typically viscous materials, so to reduce their viscosity, some alkyd paints are formulated with solvents to adjust the viscosity and facilitate application. Solvents help thin the resin, making it easier to apply and ensuring a smooth, even finish. They also play a role in drying time, flow, and surface properties such as gloss. While solvent-based alkyds offer desirable properties, they are facing increasing scrutiny due to environmental regulations related to volatile organic compounds (VOCs). To reduce solvents in alkyd mediums and paints, paint makers have three main options:
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Long-oil alkyds – Extra fatty-acid chains lower viscosity naturally.
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Reactive diluents – Drying oils, such as walnut or safflower, act as both a thinner and a binder, polymerizing into the film.
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Pre-gelled resins – Thixotropic gels provide a brushable consistency without the need for a liquid diluent.
Each approach raises the oil content, so fat-over-lean considerations still apply.
Product Case Studies
Here are some examples of mediums and paints that offer solvent-free or low solvent content alkyds for artists:
Gamblin Solvent-Free Gel
Gamblin’s SDS lists only alkyd resin, vegetable oils, silica, and a trace of propylene glycol; no hydrocarbon distillate is present (Gamblin Artists Colors, 2023). The company’s website confirms VOC < 10 g/L⁻¹ and markets the gel for alla prima painting (Gamblin Artists Colors, 2025).
Verdict: Meets the practical solvent-free test.
M. Graham Walnut Alkyd Medium
The 2021 SDS indicates a flash point of 215°F, VOC%, and no flammable symbol (M. Graham & Co., 2021). Walnut oil is the primary diluent, so the medium behaves like a faster-drying oil.
Verdict: Also solvent-free in practice, but nut-oil allergies should be noted.
Winsor & Newton Griffin Alkyd Colours
The Griffin SDS discloses 10–30 % hydrotreated light petroleum distillate—standard odorless mineral spirits (Winsor & Newton, 2015). Its VOC is roughly 250 g/L⁻¹, triggering a flammable-liquid warning.
Verdict: Fast-drying, but not solvent-free.
| Product | Added Hydrocarbon | VOC (g/L¹) | Flammable Pictogram | Meets Practical Definition |
|---|---|---|---|---|
| Gamblin Solvent-Free Gel | None | < 10 | No | ✅ |
| M. Graham Walnut Alkyd | None | 0 | No | ✅ |
| W&N Griffin Alkyd | 10–30 % OMS | ≈ 250 | Yes | ❌ |
Reading an SDS: Five Quick Checks
A Safety Data Sheet (SDS), formerly known as Material Safety Data Sheet (MSDS), is a document that provides comprehensive information about the hazards of a chemical product, including its physical and chemical properties, potential health hazards, fire and explosion hazards, and recommended safe handling and storage procedures. For flammable liquids, the SDS is crucial for understanding the risks and taking appropriate precautions. Here are the sections of an SDS to check for the presence of solvents:
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Section 3 – Composition: Look for “distillates (petroleum)” or CAS 64742-xx-x.
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Section 2 – Hazard Symbols: A true solvent-free medium should not display the flame symbol. See Notes below.
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Section 9 – Physical and chemical properties: VOC or volatile content should be at or near zero.
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Signal words: “Warning: Flammable liquid” is a giveaway.
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Revision date: Download the latest sheet; formulas change.
Best Studio Practices
Even when using solvent-free alkyd mediums and paints, follow these studio practices to ensure personal safety:
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Ventilate even with solvent-free alkyds; oxidation releases aldehydes (Gamblin, 2025).
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Immerse oil-soaked rags in water to prevent spontaneous combustion.
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Limit the medium to about 25% of the paint mixture to avoid overly thick layers.
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Test walnut-based products if you or your students have nut allergies.
Common Misconceptions
There are many misconceptions about solvent-free painting materials that are frequently discussed in forums and videos. Here are just a few:
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“Non-toxic” means harmless. Under ASTM D4236, a product may still contain cobalt driers below hazard thresholds (Solvent-Free Alkyds brief, §5).
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“Solvent-free” equals “VOC-free.” VOCs measure what evaporates, not what was added. Gamblin’s gel contains a small amount of propylene glycol, which is technically a solvent but not regulated as a VOC (Gamblin, 2023).
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All alkyds dry overnight. Dry time depends on film thickness, ambient humidity, and pigment load. Solvent-free gels often need 48–72 hours for thin films (Gamblin, 2025).
The Final Word on Solvent-Free Alkyd Mediums
“Solvent-free” has no single legal definition, yet a practical studio standard exists: no intentionally added hydrocarbon solvent and VOC ≲ 0.5 %. Both Gamblin Solvent-Free Gel and M. Graham Walnut Alkyd Medium satisfy that test. Winsor & Newton Griffin Alkyd, while excellent for rapid work, still relies on mineral spirits and should be treated like a traditional alkyd medium. Artists should verify claims through the SDS, keep good ventilation, and remember that solvent-free does not mean risk-free.
Bibliography
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ASTM International. ASTM D4236-16: Standard Practice for Labeling Art Materials for Chronic Health Hazards. West Conshohocken, PA, 2016. A specification that defines when art materials must carry chronic-hazard warnings but sets no quantitative solvent limit. https://www.astm.org/d4236-94r21.html
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Federal Trade Commission. “Eco-Friendly and Green Marketing Claims.” Last modified March 2021. Explains how “free-of” claims must reflect only harmless trace amounts and no intentional addition. https://consumer.ftc.gov/articles/eco-friendly-and-green-marketing-claims
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Gamblin Artists Colors. Safety Data Sheet: Solvent-Free Gel. Revised May 1, 2023. Lists composition, flash-point, and confirms absence of hydrocarbon solvents. https://gamblincolors.com/wp-content/uploads/2023/05/SDS-Gamblin-Solvent-Free-Gel-2023.pdf
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Gamblin Artists Colors. “Solvent-Free Oil Painting.” Accessed July 12, 2025. Web page outlining the company’s solvent-free gels, fluids, and safflower cleaning system. https://gamblincolors.com/studio-safety/solvent-free-painting/
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ISO. ISO 14021:2016 — Environmental Labels and Declarations: Self-Declared Environmental Claims (Type II). Geneva: International Organization for Standardization. Defines requirements for marketing terms such as “solvent-free.” https://www.iso.org/standard/66652.html
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M. Graham & Co. Safety Data Sheet: Walnut Alkyd Medium. Effective January 27, 2021. Reports VOC 0 % and no flammable classification. https://mgraham.com/wp-content/uploads/2023/04/M.-GRAHAM-OIL-COMBINED-SDS-SHEET-032023.pdf
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M. Graham & Co. Material Safety Data Sheets. May 2011. An older compilation confirming 0% VOC for walnut alkyd. https://mgraham.com/wp-content/uploads/2011/05/Graham-OilColorsAndMediums-1-11.pdf
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Solvent-Free Alkyds Working Brief. “Solvent-Free Alkyds: Clarifying Claims for Artists.” Unpublished internal memo, 2025. Provides a comparative analysis of three alkyd products and the regulatory context.
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U.S. Environmental Protection Agency. 40 CFR Part 59: National Volatile Organic Compound Emission Standards for Consumer and Commercial Products. Updated July 10, 2025. Establishes VOC content limits for paints and coatings. https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-59
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Winsor & Newton. Safety Data Sheet: Griffin Alkyd Fast Drying Oil Colour. Revision 5, November 17, 2015. Lists 10–30 % hydrotreated light distillate and associated hazard statements. https://www.jerrysartarama.com/media/pdfs/winsor-newton/W%26N-GRIFFIN-ALKYD-OIL-COLOURS-MSDS-SHEET-2017.pdf
Notes
The “flame” GHS (Globally Harmonized System) symbol indicates that a chemical is flammable, self-heating, emits flammable gas, is self-reactive, or is an organic peroxide. This symbol is used to alert individuals to potential fire and explosion hazards associated with these types of materials.
