Fashion has a glow on. Belts, bags, shoes, sweaters, you name it, have taken on a patina all their own.

Not that there haven't been metallic treatments before, but this year's lode makes one wonder if the airport metal detectors will hold out. And for the end of the season, wags are predicting meltdowns, not markdowns.

The gilt touch was revived by European designers about two years ago, at first showing up as piping on shoes, as embroidery, threaded through fabrics. The idea seemed new because this time gilt was geared to day. By last spring, metallic accessories began to show up on shelves here, attracting buyers looking for something--in view of the economy--to brighten up old clothes.

The buying of things metallic is easy; keeping them bright and shiny is not. Once they lose their original shine, in fact, it is usually impossible to restore the same glow.

The problem starts with the way the metallic effect is achieved. In almost every instance the metallic glow comes from a surface sprayed or laminated on a non-metallic surface. Treatment varies from item to item: Bronze Shoes

The surface--created by pressing foil onto leather--is very delicate and subject to cracking, wrinkling and peeling.

"It is the luxury material of the 1980s," claims Caroline Geller about the bronze leather used, for example, in Geoffrey Beene shoes.

Beene Bag shoes now have this warning enclosed in each box:

"The laminate is tender and has a tendency, in some instances, to look wrinkled. In addition, if scuffed or abused it is difficult to repair. These facts necessitate our advising you that we cannot guarantee this material."

"Throughout history in fashion we have dealt with delicate materials and just have to recognize them as delicate," defends Irv Silbergeld of Beene Bag shoes. "The luxury look is part of the appeal as well as the problem."

Geller says that some of the metallic surface may be restored with oil paint used by framers, but the results are often temporary. Metallic Vinyl Totes

The problem is virtually the same for synthetics, since the metallic is only a surface treatent.

"There is nothing you can do to the bag but wipe it with a damp cloth," says Shirl Miller, who has sold more than 100,000 metallic vinyl totes since introducing them less than a year ago.

The bronze shoes she bought in Paris several months ago "are now gold and peeling, and I could care less. It is fun and fashion, and I'll just wear them this way." Metallic Leather Clothing

Expect some loss of the finish in cleaning because metallic is usually just sprayed on the surface, warns Norman Oehlke, chief analyst at the International Fabricare Institute.

A professional leather and suede cleaner may try to respray the item. "But even with a careful mix of color," says Oehlke, "there may be a slight variation in the shading." Lurex Sweaters

"You can't expect a decorative metallic yarn to wear like denim," warns Oehlke. Most gold threading in knits or woven fabrics, he explains, is achieved by laminating metal to plastic filament. "They don't use a strip of metal by itself because it would be too weak."

"The loose knit," he says, "leaves the possibility that sharp edges of the metallic filament will weaken the yarn." Loose construction also can cause snagging and abrasion.

"Metallics are prone to corrosion and discoloring from perspiration, like any metal," adds Oehlke. "Anything heavily stained with perspiration should be taken care of right away."

Oehlke urges paying close attention to the care label. "The maker is responsible for colorfastness of all the garment--including the trim--to normal wear-and-care procedure, where the care is done according to the label."

Any consolation in the fact that even real gold is subject to changes in color?

Alida Morgan, one of the owners of The Right Stuff in Georgetown, recalls dealing with tarnished clothes when she was an assistant in clothing restoration at the Metropolitan Museum of Art.

To restore for exhibition an elaborate gold dress worn by Lillian Gish, "We gently spritzed the dress with distilled water. Overnight it turned black and in the morning by gently finger-polishing the garment with chamois or a cheesecloth, the gold was restored."

(Footnote: Morgan paints her cowboy boots successfully, she says, with gold paint from an auto-supply store.)

Despite potential problems of care, it's unlikely that the metal urge will wane for awhile. And even those not yet captivated by the glow may take a shine to it during the holiday season.

Next?

Silbergeld of Beene Bag shoes is predicting pewter as the big color after bronze and gold, and then silver and chrome. (People like Woodward & Lothrop fashion director Nancy Chistolini are joking that they're already "ahead of the game." Her once-bronze tote is now more like pewter.)

Designer/manufacturer Shirl Miller--she of the $47 metallic vinyl tote--is hardly behind. She's now selling a portfolio ($37) incorporating three different metallic tones. CAPTION: Illustrations 1 through 6, Olive wool, mohair and Lurex sweater by Adri from Garfinckel's, $180, Beene Bag bronze pumps with wooden heel at Woodward & Lothrop, $66, Twisted headband in gold, by Riviera at Garfinckel's, $20, Gold leather and metal belt from Bloomingdale's, $95, Bronze leather and snakeskin-look envelope bag from Hecht's, $35, Andrew Geller's short-cuffed swashbuckle boot in bronze man-made material, from Woodies, $60. Illustrations by Martha Vaughan; Picture, The ultimate bronze leather camisol (Evermore $240) worn by Sophie engelhard, an owner The Right Stuff. By John McDonnell -- The Washington Post