IN THE Washington area, as in other parts of the country, a select number of dry cleaning companies know how to clean leather furniture. Ram Leather Care, which counts the Watergate apartment complex among its clients, is one of these."Cleaning leather is a tricky thing -- you really have to know your business," says a spokeswoman for the Association of Interior Decor Specialists, Inc. (AIDS), the area's leading fabirc cleaaning trade association. The only company AIDS knows of in the Washington area that cleans leather upholstery is Ram Leather Care.

Joe Lothrop, president of Ram Leather Care, says "Although a piece of leather clothing or furniture will last longer than you or I -- it's nearly indestructible -- keeping that piece of leather in good condition during its lifetime is another story."

Leather upholstery must be cleaned slowly and painstakingly by hand, which is one reason the process isn't more universal. Gary Holum, founder and president of Servco Enterprises in Spokane, Wash., says the process is not so difficult, but it "people who are interested enough and capable enough to do it well." Both Holum's and Lothrop's firms say the refinishing procedure, which is the key part of cleaning leather upholstery, takes as long as five or six days.

Like Lothrop's, Holumn's company is the only one that cleans leather upholstery in its area -- most of upper-northwest United States. (Holum has given workshops in Spokane on leather cleaning and recently has been asked to tour the country and lend his expertise. Last October he held an international workshop that attracted not only foreign firms but "a good cross section of our country. I was surprised that so few people know anything about leather upholstery cleaning.")

Leathers are divided into two groups: finished and coated leathers and suede or open leathers. Finished or smooth leather is easy to maintain.It is the hair side of the animal hide, tanned and sealed.Tanning means that the leather skin has been cured, or processed, to remove and odors and impurities. The sealing process is one that chemically seals the pores of the animal skin. This sealed finish reacts like a painted surface when it gets wet, so water and other spills can be easily washed off. Motorcycle jackets are often made of smooth leather.

Open leathers are more difficult to clean. Open leather comes from the inside of the animal hide, and the pores of the skin are not sealed, just tanned. Open leathers, such as suede, are susceptible to staining from just a few raindrops.The finer the suede, the more it reacts to water.

Day-to-day maintenance of leather is simple. Dry vacuuming is all that is needed. Suedes and other open leathers should also be brushed with a soft wire brush. Holum warns: "Don't attempt to spot-clean suede with either a wet or dry solution -- this is how it gets stained."

A major cleaning should be done by a professional, says Holum. It isn't cheap, but if the leather piece is good, the cost is worth it. Leather furniture itself is expensive -- armchairs range from $600 to $1,200, while sofas go for $1,000 to $3,000 -- that's one reason the cost to clean them is also high. Most leather upholstery cleaners charge about $150 to $175 to clean a leather chair and between $200 to $400 to clean a sofa.

To start with, a good professional cleaner will repair cuts and cracks in the leather before cleaning. Then an oil base is rubbed into the leather to restore any oils the leather has lost. The oil base helps maintain the leather's resiliency and flexibility. All of this is followed by an extensive five- to six-day refinishing process. Each step in the process is done by hand.

With smooth leathers, the color of the leather can be changed. Holum recalls a psychiatrist's couch he recently dyed from bright pink to charcoal gray. "I guess that pink color wasn't conductive to calming people down," laughs Holum.

For leather furniture whose original shade has faded due to sun exposure or wear, Scott Marsh, corporate manager of Tandy Leather in Hyattsville, suggests rubibng your leather piece with Fiebing's Four-Way Care. "This will refurbish lost oils to your leather and give it a nice sheen," says Marsh. "Just rub it in. Let it dry. The polish the furniture with a soft cloth," he says.

If the leather is severely faded you may want to dye it a shade close to its original color. To dye leather yourself: prep the surface with a denatural alcohol (wood alcohol), which can be bought at most hardware stores. The alcohol opens the leather skin's pores and removes any old wax. Then apply an oil-based surface dye (Tandy's uses a spray called Magix Shoe Dye).Finally, put on a wax sealer. The sealer, also supplied by Tandy's, glues any loose dye pigment in place so it won't rub off on your clothes. "Make sure," warns Marsh, "that you don't use an acrylic surface dye since it will crack if stretched. Acrylic dye is best used in repairing scratches."

"And," he adds, "beware of toxic dyes. Some places still sell them despite the fact that they've caused paralysis when swallowed by young children an blindness when it gets into the eye -- it burns the optic nerve."

Tandy Leather, which sells leather maintenance supplies, but does not do any leather repairs itself, also carries an acrylic surface dye that can be used to make cracked or gashed leather look presentable again. Marsh advises that you water down the dye and after applying it, allow it to penetrate into the cracks. It wil leave the rest of the leather surface untouched.

Stains in leather furniture are easier to remove from smooth leather than from open leathers. Lothrop says, "If a stain has remained in suede or cowhide anywhere from 10 days to three weeks, it probably can't be removed." He suggests that when you do stain an open leather, you bring it immediately to a professional upholstery cleaner. For severely stained furniture, you might be better off dying the entire leather piece another shade.

"Also," advises Lothhrop, "don't think that by rubbing saddle soap into leather you're getting it cleaned. Saddle coap is only a conditioner. Rubbing it into a piece of leather is like rubbing Ivory Snow into a dress and never washing it out. Saddle soap is okay for briefcase and boots because what it does is cover the stain -- it does not remove it."

Other no-nos:

Don't use K2R spot cleaner on leather. It may shrink or distort the material.

Beware of suede dye: Ten coats of it won't hide anything. It only adds color to the existing stain pigments.

And finally, don't bring you leather upholstery to Ram Leather Care during the autumn months. This is when they're backlogged with metropolitan Washington's leather coat owners. Leather furniture is handled now through September. Ram Leather Care, 3014 Columbia Pike, Arlington, Va. (703) 521-5600. And for leather care supplies: Tandy Leather, 7452 Annapolis Road, Hyattsville, Md. (301) 577-3282.