Oil Painting in Educational Settings
A Guide to Studio Safety
Best Practices | Recommendations | Technical Information
For 600 years, oil painting has been the preeminent painting media. Oil painting has documented our cultural heritage and has endured and evolved through the advent of photography, the modernism of the 20th century and into the digital age.
Why does oil painting remain relevant? Because no other media carries the same raw power of communication. No other media gives artists the same intensity of color and breadth of mark-making possibilities. There is nothing more natural and enduring than oil painting.
Oil painting practice and instruction continues to grow in universities across the country. And standards have evolved over recent decades. Turpentine was once used in virtually all painting studios. Today it is a thing of the past. Leading schools and instructors have incorporated higher standards, which we share, for a safe studio environment and the responsible management of waste.
At Gamblin these ideas are not just important to us, they are the founding ideas for our color house. The objective of this guide is to provide two things for you: the proven solutions Gamblin has contributed on the materials side of the equation, and the systems developed by leading schools like the Rhode Island School of Design.
Our mission is to lead oil painting and printmaking into the future. This guide is intended to help Instructors, Heads of Departments, and Facilities Managers in schools to have painting studios that are as safe as possible for students and the environment.
Where does the oil in oil painting come from? How does it compare with other mediums?
The Nature of Oil Painting
Linseed oil is pressed from the seeds of the flax plant. The flax plant has been the heart and soul of oil painting, giving us both the oil our colors are bound in and – from the stalks of the plant – the linen we paint on.
Linseed oil naturally dries faster than other oils and retains greater strength and flexibility as it ages. We also use safflower oil in some colors. Not only are both of these vegetable oils completely non-toxic, they are also both used in moisturizers, cooking oils, food and vitamins.
Linseed and safflower oils do not give off “fumes”. In fact, these oils take in oxygen as part of their drying process. Gamblin Artist’s Oil Colors do not contain solvent, nor do they require any solvent for their use.
The pigments used in oil colors are the same pigments found in watercolors, acrylics, and pastels.
Since we do not use any pigments based on lead, mercury, or arsenic, with very few exceptions our colors are completely non-toxic and do not require health labeling of any kind.
Artist’s oil colors are simple mixtures of pigment and linseed oil. Acrylics, by contrast, are more complex formulas of plastic, water, pigment, ammonia, and other chemicals.
Oil colors pull oxygen out of the air to dry – there is no “off-gassing” with oil colors. In comparison, acrylics dry by the evaporation of their volatiles, such as water, ammonia, and propylene glycol.
This diagram illustrates the oxidation of the linseed oil binder in oil colors. Oxygen enters the paint layer, which starts the polymerization (linking up) of linseed oil molecules into chains. This locks-in the pigment (shown in blue) to create what we experience as “dry” paint layers. This process takes several days to become “touch dry,” though the oxidation of oil paint layers continues after that.
In acrylic colors, the pigments are bound in a longer-chain acrylic polymer. Acrylic colors dry by the evaporation of volatiles – first water, upon which the paint layer feels dry to the touch, and then ammonia and propylene glycol over days and weeks.
After our testing of these materials, we have come to believe that water-miscible oils mean far too much artistic compromise for no real improvement in safety for artists or the environment. We encourage the use of traditional oil colors and contemporary or solvent-free painting mediums rather than the “new” water/oil paints for three reasons:
- Artists can experience the luscious working properties of traditional oil colors without the compromises that water-miscible oils place on the painting experience.
- History has demonstrated that chemical additives can harm oil paint films as they age. We know that conservation scientists are interested in these issues, but much is still unknown about the aging of water-miscible paint films.
- Oil painters who carefully use traditional oil colors wash nothing down the drain and into the watershed.
Gamblin Artist’s Oil Colors themselves are non-toxic when used as recommended. Linseed, poppy and safflower oil are natural “drying oils” that absorb oxygen from the air and dry naturally. Because they do not evaporate, there are no health hazards associated with them regardless of the type of oil or how it is produced.
Gamblin’s stance on water-miscible oils and studio safety, in general, is that the toxicity concern surrounding oil painting has nothing to do with the colors themselves, but the solvent used to thin oil colors and painting mediums.
Our approach is to offer Gamsol, the mildest form of Odorless Mineral Spirits. Gamsol is used for thinning oil colors and for brush/studio clean-up and is used to formulate our contemporary painting mediums. We also offer the broadest range of solvent-free painting mediums, which allow for the safest possible painting studios.
How do I choose and manage solvents in our oil painting studio?
Solvent is traditionally used in oil painting for brush and studio clean-up and to thin oil colors from the tube. Solvent is also a component of most painting mediums used to alter the viscosity of oil colors and speed drying. In making mediums, the solvent is mixed with a drying oil (e.g. linseed oil) and/or a resin (traditionally dammar resin or contemporary resins, such as soy-based alkyd). Gamblin’s approach to painting mediums is to formulate a range of contemporary mediums based on alkyd resin, as it allows us to create mediums with the mildest form of odorless mineral spirits: Gamblin Gamsol.
There are hundreds of different types of solvents in the world – all with unique properties and applications in various industries. A variety of different solvents have been incorporated into oil painting studios over its history. Not all solvents are created equal. Below is information on what makes Gamblin Gamsol uniquely qualified to be the standard for studio safety in classrooms and home studios. A solvent’s safety is determined by its evaporation rate, permissible exposure level and the ventilation in the workspace.
Definition of an Artist’s Solvent
The Artist’s Handbook of Materials and Techniques by Ralph Mayer and The Painter’s Handbook by Mark Gottsegen are the two definitive books on painting materials published in America. They both define the working properties of an ideal artist’s solvent the same way.
An artist’s solvent should:
- Evaporate completely
- Evaporate at a uniform rate
- Have no effect on dried paint layers
- Be chemically inert to the materials with which it is used (i.e. have no chemical reaction)
- Mix completely with the materials with which it is used
- Have no toxic vapors
- Evaporate entirely from the dried paint film within a reasonable amount of time
Many solvents on the market satisfy some of these requirements. Gamsol meets all of these requirements when used as recommended. Gamblin Gamsol odorless mineral spirits balance both performance and safety like no other artist’s solvent on the market.
Gamsol versus other solvents
Gamsol allows painters to work in traditional and contemporary techniques without compromising artistic possibilities, permanence, or their well-being. Gamsol is also reusable, and non-toxic when used as recommended.
Most solvents available to artists are produced for the industrial paint industry where solvent strength and low cost take priority over safety. Gamsol is different. It comes from a family of materials used in products that come into more intimate contact with the body, such as cosmetics, hand cleaners and cleaning food service equipment. For an artist, there are a number of factors to consider when judging a solvent’s safety. Aromatic solvents are the most harmful type of mineral spirits. Gamsol is an odorless mineral spirit which has all of the aromatic solvents refined out of it – less than 0.005% remains. In addition, Gamsol has a slow evaporation rate, a high flash point, and is not absorbed through healthy skin. Unlike other solvents, Gamsol is readily biodegradable and contains no Hazardous Air Pollutants or Ozone Depleting Compounds.