by John Clark
Today’s paints boast better technology than ever before and present painters with unprecedented flexibility. Watching paint dry – it’s synonymous with ultimate boredom. Yet, for painters of any stripe, it’s a matter of great importance.
Drying (depending on the paint, method, and the stage of the work) can involve a year, a month, a few days, minutes, or seconds. It’s a characteristic, a variable: Something a painter learns to work with and around, through trial and error. Which is another way of saying there’s plenty of impetus for innovation. For example, ever since oils first appeared in the early 1400s, various drying mediums have been employed, often to less than desirable effect, in the end. And drying characteristics taken together are only one of several variables which ultimately define a paint.
In the last 100 years, more technology has been applied to making better paints than during any similar span since a caveman first painted – because there’s simply more technology, industrial resources, and consumer demand. Automotive industry research and development, for example, has dramatically enhanced light-fastness, pigment, and color choice in paints formulated for vehicles, and the arts and crafts have been grateful beneficiaries.
As paint technology continues to evolve – more quickly now, but otherwise as it’s done for thousands of years – we’re seeing acrylics gain widespread acceptance by radically redefining the envelope in terms of flexibility.
Oils and watercolors boast higher quality, consistency, brilliance, and stability than ever before, plus new mediums to mix with for more expressive possibilities. Virtually all fine manufacturers now label tubes with pigment names, light-fastness, and permanence ratings in addition to required health safety labeling that dramatically increase artists’ working knowledge of their materials, improving results and safety.
Moreover, newer paints that you may be less familiar with, such as alkyds, water mixable oils, and heat-set oils are redefining “oil painting” to include alien concepts like “fast-drying,” dries-when-you-want-it-to, and soap and-water clean-up. Weird, huh? Not only are paints better these days, they’re easier to use, and therefore less intimidating to learn. Let’s take a closer look at the paints that are re-writing at least some of the rules.
You get choices when it comes to alkyds: alkyd mediums, and alkyd based oils. Who’s buying? Painters who love their oils, but not the drying times. This technology has been around for a few years, but acrylics had stolen the show to some degree. Now it’s reemerging from the shadows.
Polymerizing a natural oil in a reaction with an alcohol and an acid creates a resin-like substance which is then put into solution with a mineral spirit solvent to create a medium, or vehicle for pigment. “Alkyd,” as a name, derives from the alcohol-acid reaction.
Alkyd mediums speed up drying and improve flow in traditional oils. They’re ideal for glazing applications, and increasingly have become the medium of choice for oils.
Alkyd-based oils use alkyd resin as the paint vehicle, meaning the paint retains virtually all the characteristics of oils, including the use of traditional solvents, but is faster-drying (touch dry within a day), and has greater transparency and luminosity out of the tube, because the alkyd-resin vehicle can’t hold quite as much pigment as natural oils.
Alkyd-resin oils also dry to a harder film, meaning they’re better suited to craft applications, such as decorative painting, than are traditional oils. Alkyd oils can be used on wood, glass, metal, or porcelain, and they have good resistance to physical wear and weathering.
The depth and consistency of color still surpasses acrylics, while the longer working time is useful (4-8 hours of workable palette time), but not excessive (touch-dry in 18-24 hours, versus 2-12 days for traditional oils). Painters who work in acrylic primarily for speed of drying, but otherwise prefer the look and feel of oils, should definitely know about alkyds if they don’t already.
Likewise, those who have not been introduced to alkyd mediums like Liquin, by Winsor & Newton, and Galkyd, by Gamblin Artists Colors, are also in for a pleasant surprise.
A distinctly different drying solution can be found in Genesis’s Heat-Set Oils. They basically don’t dry until you want them to. All that’s required is the application of heat. The technology behind the polymer comes from medical science, where it was originally employed in bone-replacement material. Genesis re-directed it toward paint to create an innovative oil unlike any that’s ever been produced. The heat from a hair dryer is sufficient to dry the paint, which means it’s easy to accomplish. Watercolorists sometimes employ hair dryers to speed drying, and now oil painters can do the same thing.
Obviously, this can radically speed up glazing methods, while also leaving an unlimited open time for wet-in-wet work. Basically, it’s the ultimate in drying flexibility when it comes to oils.
The other, more serious downside to oil paints is that they traditionally require the use of noxious solvents like turpentine and mineral spirits for thinning and cleaning. These obviously present health and safety concerns, especially in group settings, like classes. Even though solvents have steadily been made less hazardous, especially in regard to the aromatic content.
Solvents are flammable, and they present health and environmental risks. Using turpentine in the palm of your hand to clean a brush loaded with Cadmium Yellow is just dangerous, as the solvent facilitates absorption through the skin. With these materials, it is the exposure over time that is insidious. In group settings, or home studios, the build-up of fumes can be unacceptable. Not to mention what pouring all this down the drain ends up doing down the line.
Solution? Oils that can be thinned with water. To which everyone except a chemist immediately replies, “Oil and water don’t mix.” But, in fact, they do. And the technology here isn’t modern. Emulsions have been in use for thousands of years.
By creating an emulsion with water and a natural oil vehicle, to much the same effect as when water is emulsified in acrylics, you get an oil paint that doesn’t require the use of solvents for thinning or cleaning. Healthier, easier, safer, but still oil.
IRIDESCENTS & INTERFERENCE
Yes, one is a time-honored penalty in football. In painting, it’s an occasion to have a little fun, rather than hang one’s head.
Take mica platelets 1 to 2 microns in thickness, coat them with an extremely thin layer of either titanium dioxide or iron oxide, or both, and you’ve got paints with pearlescent qualities producing various colors and hues. These very thin, highly reflective, and transparent platelets can, by virtue of their shape, be easily oriented into parallel layers within a transparent medium. Light is ultimately reflected by many different layers. Multiple reflections from microscopic layers is what produces a shimmering or pearlescent effect.
Interference colors are a sub-category of the iridescents, wherein the properties of light interference are put to use to achieve color flips between a main color and its complement. It gets a little complicated, but it’s worth understanding, as these sorts of paints are everywhere. According to Golden Artists Colors:
“Light interference results from concurrent multiple reflections and refractions of light. If the interference is constructive in nature, the light waves reflected from the different layers will be `in phase,’ and a strong color stimulus results. With interference colors, a specific thickness of the titanium dioxide layer allows only a narrow band of wavelengths of light (representing a certain color) to be reflected in phase, while all other reflected wavelengths of light (colors) undergo destructive interference and are not observed. As these pigments are transparent, a portion of the light will be transmitted and the resulting color will appear as the complement to the reflected color.”
Pretty simple, eh? Bottom line, these paints represent the shape of what’s to come in paint. Because they’re acrylics, a virtually limitless number of combinations between base-coat color, mediums, transparent colors, interference and iridescent colors, and gels and glazes can be had as a result, for fine art, decorative or home-decor applications, to name only a few.
Paints evolve because creativity is always looking for more effective means of expression. Although art materials have evolved at a rather slow pace historically, the development has been relative to economics and technology (chemical and industrial).
Painters for their part spend a great deal of time experimenting with technique and materials. They don’t change quickly once they’re comfortable. Put the two trends together, and this hasn’t been a market that threatens to outpace retailers.
But a lot has changed, and serving painters increasingly means understanding the wide variety of applications to which different paints can now be put. The “boxes” we used to put specific paints into don’t apply like they used to.
Painters are only beginning to imagine the possibilities. They’re only now moving away from the traditional paints they’ve been trained to buy, and into the quinacridones, naphthols, pyrroles, phthalocyanines, and the other synthetic organic pigments developed by organic chemists.
Flower painters have incredible, luminous magentas, pinks and purples never before available. Landscape painters are trying Quinacridone Gold in glazes instead of Raw Sienna.
An entirely new generation of colors and paint formulations is here, and more are on the way. Just as new materials and possibilities were inherent to the rise of Impressionism, and play such a large role in modern painting, the current and coming generations of paints will have a profound influence.
earth pigments: Family of pigments comprised mainly of those typically found in the ground, like siennas and umbers. emulsion: A stable mixture of two liquids that don’t normally mix. One liquid is dispersed within another liquid by chemical or mechanical means.
glazing: Applying transparent layers of paint upon previously dry layers.
inorganic pigments: Second pigment family, introduced through the 18th and 19th centuries, comprised of metals such as cadmium, cobalt, iron and manganese. Colors gray easily, good for natural light painting.Light-fastness: The extent to which a pigment is or isn’t broken down by long term exposure to light rays. Rated from I to 5, with I being most permanent, and I or 2 suitable for artists’ use.
medium: Liquid added to paint to alter working characteristics such as consistency, flow, drying time, and/or gloss.
permanence: Manufacturers’ rating of the paint’s overall durability, including the stability of the vehicle film, and not just Iight-fastness of pigment
pigment: A coloring compound that remains a discreet particle in suspension with a vehicle.
polymer: Chemical compound consisting of repeating structural units (monomers} linked together:
synthetic organic pigments: Third pigment family, these come from organic (carbon-based) chemistry developments in the 19th and 20th centuries, and include compounds such phthalocyanines, quinacridones, naphthols, perinones, diarylides, and dioxazines, among others. High-key colors, mostly transparent
Vehicle: The liquid in which pigment is suspended (linseed oil, acrylic polymer emulsion, gum arabic). Upon drying, the vehicle forms a paint film that “locks” pigment into place.