Aesthetes of a certain temperament think of watercolors as a secret vice, something they love but dare not praise in modernist circles. There, the medium's old-fashioned virtues are often scorned as quaint or irrelevant.

While contemporary fashion favors big, sprawling conceptual art produced by studio teams, watercolors are intimate -- or at least "sofa sized" -- and handmade by the signator rather than a hireling. They display contradictory skills -- spontaneity and planning, loose brushwork and total paint control, keen observation and happy accidents. Tricky stuff, that.

For appreciators of the medium, the Bloomington Art Center has a treat in the 91st annual National Watercolor Society Traveling Exhibition. The show features 30 exemplary paintings from artists in 14 states plus Australia and South Africa. They are a subset of 100 award-winning pictures picked from nearly 1,000 entries in an international competition.

Given Minnesota's rich watercolor tradition, it's no surprise that winners include Minneapolis artist James Warren Kuether and the internationally known Duluth talents Cheng-Khee Chee and John Salminen.

Old subjects, fresh challenges

If watercolorists are biased toward traditional subjects -- landscapes, portraits, still-lifes -- that's doubtless because their challenges are infinite. Kuether's luminous "The Bird's Nest" is a marvel of design. More than 2 feet tall, it depicts a flurry of tropical leaves whose sail-like blades flare around the almost camouflaged nest of a small white bird. With crisp lines and clear, transparent hues, Kuether defines stems edged in rose and violet, curling sun-bleached leaves and pine-dark shadows heavy with the torpid heat of midday.

Salminen takes a looser approach in "Shanghai Construction," a skyscraper's-eye view of a sprawling construction site whose vast footprint slices into an urban fabric. His watery pigments roll across the scene like a darkening cloud, shifting from pale yellow to a bruised greenish purple where the new and old city meet.

At more than 3 feet wide, Cheng-Khee's "Crabs" is a brooding tangle of beady-eyed creatures apparently competing for dominance in murky water, a struggle that invites metaphoric interpretation.

Tone and texture

Watercolorists pride themselves on their ability to suggest myriad textures, as Virginia artist Michele Rea does in "Old Cemetery Gate," a close-up of an ancient, rusting hinge tying a scabrous door to a patched and worn brick wall. Next to that work, a painting by Guan Weixing of North Carolina simultaneously describes the stubbled cheeks and sun-squinted eyes of a man with two gold teeth wearing a pale-plaid cotton shirt at midday before a stuccoed wall. Skin, beard, fabric, time-of-day, locale and dentistry -- all in a few strokes of a brush. Cool.

A fast-drying medium, watercolor demands dexterity and premeditation for best results, as seen in "Little Billy," by Louisiana artist Judi Betts. The coy title is a bit too cute for Betts' sophisticated encounter with a herd of goats. With their floppy rabbit-like ears and curious eyes, the animals are full of personality. After capturing their awkward grace in sepia tones, Betts enlivens the image with pale washes of complementary colors (green/orange; rose/blue) that introduce unexpected sophistication to a homey image.

Illusion and design define "Miss American Pie" by Laura Allums Mitchell, also of Louisiana. A still life of apples in a gleaming metal bowl on an undulating cascade of red/white/blue striped fabric, "Pie" is a gaudy cornucopia of painterly problems, from how to "shade" white stripes and fabric folds, to creating illusions of metal and reflections-in-metal.

In the flesh

Portraits are a special challenge with their myriad skin tones, hair textures, expressions and gestures. In her portrait of two black South African singers, Robin Van Den Barselaar conveys the beauty of the women's skin and the intensity of their performance under a nightclub spotlight. The picture's freshness is even more remarkable because dark watercolors turn muddy if overworked and, traditionally, they can't be topped up with lighter hues, as oil pigments can.

These artists have their tricks, however, as seen in "I Was in the Neighborhood," by California painter Will Bullas. He sketched in his subject -- a guy in jeans, T-shirt, aviator glasses and helmet -- with transparent watercolor that stains the paper and generally can't be altered. Then he used a hair-dryer, sponges and toothbrushes to spatter on shadows and enhance volumes and details.

Long associated with leisure, watercolors are sometimes condescendingly dismissed as what serious artists do on vacation (think Winslow Homer in the Bahamas, John Singer Sargent in Italy). And because their pigments fade if long exposed to light, they can't be displayed permanently as oil paintings can. Worse yet, they're "retinal." That is, they appeal to the eye, a quality that art snobs have been dissing since Cezanne tossed a barbed bouquet to Monet whom he called "only an eye, but my god, what an eye."

Such are the burdens of disdain that the medium carries. But forget all that and simply delight in the skill, training and design savvy on display in Bloomington. The show is a gem. • 612-673-4431