As collecting original paintings is becoming more popular and mainstream in the sports memorabilia hobby, this column is a beginner's guide to identifying the different types of paint (oil, acrylic, tempera, watercolor, gouache, pastel, encaustic), and how to identify reproductions of paintings.
The common types of paint in fine art paintings:
Oil painting is the most famous form of fine art painting and the most common in antique days. It has been used for centuries and is still used by artists. The Mona Lisa, Whistler's Mother, Van Gogh's Starry Night and countless other famous paintings in museums are oil paintings. Oil paint is slow to dry and usually shows the brush strokes. The brush strokes are physically raised as with a relief map. You can see and feel the brush strokes. Especially bold brush strokes are called impasto.
Oil paintings were usually varnished which can make them glossy. The varnish can darken and gather dust and grime over the decades and often has to be replaced.
Oil colors can be subtle, dark (if antique) and have a glowing, translucent quality. When restored, the varnish is stripped, new varnish is added that makes the painting seem bright and new again.
Old oil paintings often have a minute crackling or 'alligator skin' quality to the surface of the paint from the aging.
Acrylic is a synthetic plastic version of oil paint, and very closely resembles oil paint. It was introduced around the mid 1900s. Due to its invention date, a painting identified as acrylic clearly cannot be from 1910 or 1880. As with oil paint, acrylic can be thick on the canvas and has bold, physically raised brush strokes. Artists use oil and acrylic paint today, so if the painting is modern it can be hard to tell if it is oil or acrylic. Though Acrylic paintings tend to be more plasticy looking, with more pallid colors. Oil paintings tend to be glossy, while acrylics often (not always) are matte.
Tempera, often called egg tempera, is an ancient type of paint and painting that pre-dated oil paint in popularity. The paint usually has the color pigment mixed in egg yolk, thus the name egg tempera.
Many ancient Egyptian and Western Medieval paintings were tempera, as are the paintings by Michelangelo and Botticelli. Tempera was the most popular form of painting until the 1500s, when it was replaced by oil paint. Some artists today paint in tempera. Twentieth century American Andrew Wyeth is the most famous modern egg tempera painter.
Due to the distinct paint qualities, tempera has a look and feel much different to oil and acrylic painting. Tempera paint is thin in consistency, tranluscent and dries very fast. This means the artist painstakingly paints in careful, thin brush strokes, brush stroke by brush stroke, and slowly adds up the paint lines to create the overall detail. When you look closely at a tempera, the graphics are usually made up of thin lines, often overlapping and cross hatching to build up color and detail. These lines mean the painting often closely resembles a fine color pencil drawing.
There are no big, bold, thick brush strokes or heavy globs of color as can appear on oil and acrylic paintings. Tempera paintings usually have a matte finish.
Tempera paintings tend to have overall brighter colors and with less contrast in the details. Notice the lack of contrast in the face of the Botticelli painting of the woman shown above. The shadows of her skin are lighter and more gradual than the stark dark to light that often appears in oil paintings. The lighter contrast is because the artist created the details and colors by carefully building them up thin overlapping line by thin overlapping line.
Watercolor is a thin, watery, translucent paint that has a signature 'wash' look. As the paint is translucent, you can see through it to the paper behind and can often see pencil sketches and outlines behind. The pencil sketches and outline often give away a painting as a watercolor. Under magnification, you can see how the ink is applied in different amounts to the paper. Unlike oil or acrylic paint, there are no physically raised brush strokes you can see and feel.
The only non-painting process that can very closely mimic watercolor is a form of handmade lithography sometimes called wash lithography. At eye level and even under magnification, this lithography looks like watercolor paint. Luckily, it is a fine art form of lithography, often used on 19th century and early 20th century items so has value. One way to tell the difference between the watercolor and lithograph, is to apply a wet q-tip to a part of the item. The water-soluble paint will come off on the cue tip but the non-water soluble lithography ink won't. If it has the background sketch or outline, then it is watercolor. Clearly, this is usually not a desirable thing to do to a painting, and some will never do it.
Gouache is opaque watercolor. Chalk is added to watercolor to make it opaque. As with watercolor, it is often on paper and there are no to very slight raised brush strokes. Gouache has a different solid look and style to watercolor. Gouache is somethings used with watercolor in the same painting, so there will be areas of opaque and areas of translucent ink. Watercolor and Gouache are often used together, with transparent and opaque parts in the same panting.
Pastel, including oil sticks, is a painting medium where the artists uses sticks of pure powdered pigment to draw, instead of brushing paint on paper or canvas. A pastel painting can generally resemble oil and acrylic paintings with raised brush strokes, but has a distinct drawn crayon look. It can resemble a thick crayon drawing.
Encaustic painting is an ancient wax-based painting technique that has been revived in recent years. Using hot bees wax as the material to hold the color pigments, an encaustic painting is easy to identify at a museum or gallery because it has a distinct waxy appearance and often even a waxy smell. It usually has bold physically raised brush strokes. It was used by the ancient Greeks and Egyptians, with the picture here showing an ancient Greek encaustic painting. It was rarely used for hundreds of years after due to the universal popularity of oil paints. However, the technique was revived in the 20th century and you can likely find a local beginner's class on how to make your own encaustic paintings.
Identifying reproduction paintings
Many paintings have been reproduced. Reproductions range from the blatantly obvious to the more deceptive. I don’t have to explain to you that the Mona Lisa on your umbrella or coffee cup isn’t the original. However, reproductions can be more realistic, can be on canvas, framed and even with fake brush strokes. A number of well-known artists have had their paintings officially reproduced. Leroy Neiman, Norman Rockwell, Salvador Dali and Thomas Kincaid come to mind.
Identifying a reproduction is usually easy, though there might a few trickier instances. The following are a few things to look for:
** If a 'painting' is a called a serigraph, screenprint, lithograph or giclee, it's not a painting. It's a print. Those names are types of printing processes.
** If an artwork is limited edition numbered (say "75/100" or "10 of 50"), it makes sense that it's a print or a photograph and not a painting. Most paintings are one-of-one.
** A fine color dot matrix pattern under high magnification identifies reproductions. A photomechanical or digital reproduction of a painting or photograph will translate the original into a fine pattern of different tiny color dots. With a strong magnifying glass or microscope examine a magazine photo or picture postcard to see what this dot pattern looks like. A painting is made with brush strokes of solid paint and will not have this maze of dots throughout the image. If you’ve identified this dot pattern you can stop. It’s not a painting. It’s a reproduction.
** With an oil or acrylic painting, there will be physically raised brush strokes that you can see and feel. If you run your finger across the original Mona Lisa or your neighbor’s acrylic landscape, you will feel the brush strokes. On many reprints of oil and acrylic paintings, such as on a poster, the surface will be flat and smooth.
With real watercolor and gouache paintings there will be no raised brush strokes, the surface can feel smooth and the painting can be on regular paper. This makes reproductions of these paintings more deceptive before you take a close look under magnification and see the tell-tale dot pattern just described.
Realize that some reproduction paintings are printed on canvas and can have fake brush strokes that are raised as with oil and acrylic paintings. They can be realistic looking when hung on a wall. Happily, that tiny color dots pattern under magnification will always give them away as reproductions.
** A black light can identify many modern reproductions of old paintings, or otherwise modern paintings, as many of the modern materials fluoresce brightly under black light. In particular, the modern paper and canvas can fluoresce brightly.