(MONEY Magazine) – You don't always choose your obsessions," says Julie Lindemann, a Wisconsin photographer. "Sometimes they choose you."

Lindemann should know. She and her photographic collaborator, John Shimon, have collected—or been chosen by—more than 40 aluminum Christmas trees over the past 15 years. That places them among a growing cadre of enthusiasts who view the sparkly metal totems as legitimate objets d'art—so legitimate, in fact, that vintage trees now routinely sell for hundreds of dollars. And with the holiday season upon us, that makes aluminum trees an ideal subject to kick off MONEY's new collecting column.

Surprised? Don't be. Long derided as ironically lowbrow at best, tastelessly tacky at worst, aluminum trees are now being reassessed as minor masterpieces of mid-century space-age design, appealing to many of the same retro-minded people who like Danish modern furniture and Lichtenstein paintings. And with many baby boomers fondly recalling the aluminum-gilded holidays of their youth, the metal trees symbolize comforting nostalgia for more people than you might think. "They're the hottest Christmas collectibles right now," says Steve Marz, a publishing sales representative who belongs to Golden Glow of Christmas Past, a 1,200-member group specializing in holiday-themed antiques.

Aluminum trees' heyday ran from 1959 to about 1967. Nearly 40 years ago their bad-taste credentials were cemented in the 1965 holiday classic A Charlie Brown Christmas (in which Lucy tells Charlie Brown, "Get the biggest aluminum tree you can find.... Maybe painted pink!"). But it's now possible to view the trees without their surrounding cultural baggage and to see them for what they are: beautiful decor, cleverly designed. The wooden trunks have pre-drilled holes to accommodate the metal branches, which feature the ingeniously woven aluminum "needles." Since stringing electric lights on a metal tree can cause a short circuit, manufacturers came up with a different lighting source: an illuminated color wheel, usually positioned on the floor and aimed at the tree, creating a wondrous reflective effect—not very traditional, but genuinely resplendent. The spectacle was sometimes further enhanced by a rotating tree stand. The stands and color wheels are standard accessories for today's aluminum-tree fans.

Lindemann and Shimon, the photographers, grew up in the early 1960s around Manitowoc, Wis., where the now-defunct Aluminum Specialty Company made the first metal trees in 1959. But they didn't give much thought to the trees until moving back to Manitowoc in 1989. "We'd always see them at estate sales for like 25¢," says Shimon. "We probably passed up a dozen of them before we got the first one."

As their collection grew, the pair began exhibiting the trees in their gallery. Although they stopped the annual holiday displays in the late '90s ("We ran out of space for them all," Lindemann explains), they've documented their obsession by authoring Season's Gleamings: The Art of the Aluminum Christmas Tree (Melcher Media, $17), which appears to be the first book dedicated to the subject.

"From a design perspective, they're quite brilliant," says Lindemann. "The simplicity of the lines, the way they really do evoke a tree—just the sight of them is pretty amazing. And nobody seems to have just one. We've met lots of people who say, 'I've got five or 10 of these, and I know somebody who has 50!' People seem to want them in multiples."

One such person is Stephen Paul Jackson, a home designer with a penchant for retro design. "A friend gave me an old aluminum tree in 1992," he says. "Then someone gave me another. At first I thought they were tacky, but then friends brought their kids over to see them, and they were really fascinated by them. That's when I began to see the beauty in them myself."

As Jackson has tracked down as many colors and models as possible—"every species," as he puts it—his forest has swelled to 61 trees. He shares his collection each holiday season by finding a small storefront space in or around Brevard, N.C., calling his exhibit the Aluminum Tree and Ornament Museum (828-884-5304; aluminumtree.com).

So, is aluminum a good investment? Glen Rairigh, a Michigan auctioneer who has about 30 trees, thinks it is. "It's generational—we all collect our childhood," he explains. "They won't stay this hot indefinitely, but I expect they'll increase or at least hold their value for another five to 10 years." That's also good news if you've got an old tree in the attic that you want to sell—you'll attract lots of bidders on eBay. (See "Buying and Selling Tips," above.)

Ultimately, though, the best reason to get one of these shimmering beauties is not financial but aesthetic: They're the very definition of a cool Yule.