Helen Ingalls, left, and Hugh Shockey restore artwork at the Smithsonian’s Lunder Conservation Center in Washington.

If you have learned even a bit about caring for fine furniture, artwork and collectibles, you know that all preservation techniques are not created equal. Some actually can be detrimental to the history and resale value of a piece.

Fortunately, here in Washington we have a nearby resource, the Smithsonian's Lunder Conservation Center, to bombard with questions. The center, on the third floor of the Smithsonian American Art Museum and the National Portrait Gallery, has workrooms surrounded by glass where visitors can watch conservators in action, cleaning a painting or restoring folk art.

Its staff offers guidance, along with tips on what nonprofessionals can do to maintain their art and what is better left to the experts. One of the most important things to understand is the distinction among preservation, conservation and restoration:

-- Preservation is a way to control agents of deterioration, such as humidity, temperature, pests, light, dust and air pollution.

-- Conservation is a more involved process that includes ethics and a scientific understanding of materials. "Conservation is accepting the condition that the artwork is in ... and trying to stick to what the artists intended as much as possible," said Amber Kerr-Allison, the center's conservation paintings intern. Conservators study organic chemistry and art history and have had hands-on experience as an intern or apprentice. Some may have completed a graduate program in fine art conservation.

Restoration is less about a piece's history and more about its aesthetics. It's about making an object "look new, polished up, everything looks fine like nothing has happened to the work" if it has been damaged, Kerr-Allison said. Restorers doesn't usually reference material science or an object's background to the degree a conservator does.

It's best to take care of any piece before deterioration sets in. "Damaged and deteriorated (objects) are never the same. It's very hard, if not impossible, to completely reverse damage," paper conservator Catherine Maynor said. So knowing how and where to set objects is essential to preventing deterioration from fast-forwarding.

At home, you can keep paper, paintings, textiles and plastic objects out of direct sunlight with filtering films or curtains to prevent fading and structural weakening. (Metals, stones, and glass and ceramics in general aren't light-sensitive.)

Lightly dust your objects with a soft brush, object conservator Helen Ingalls said: Dust absorbs water, which can cause corrosion and attract insects that leave droppings.

Beware of placing objects in attics, basements and bathrooms. These rooms are prone to drastic changes in humidity and temperature, or are too hot or cold. Basements are prone to flooding and damp conditions.

If you've already noticed damage such as corrosion, instability, surface damage and grime, conservators agree it's a good idea to consult a professional. "This is not a do-it-yourself type of endeavor, especially for any objects with monetary or sentimental value," object conservator Hugh Shockey said.

Once you've determined what level of care you need, the key is finding a professional with credentials and experience. You can start your hunt by looking for a conservator who belongs to the American Institute for Conservation of Historic and Artistic Works. (The AIC established the conservator's Code of Ethics and Guidelines for Practice.) Lunder programs coordinator Julie Heath said cautioned that membership doesn't guarantee a conservator's work. Get a list of past clients and referrals to double-check a conservator's professional history.

The conservator will see the piece on site to judge environmental conditions, then write a treatment proposal estimating the time and cost of the conservation. Expect to spend US$75 to US$120 per hour for the treatment, Ingalls said. "If they're charging you US$30, they might not be that great" because they may rush through your piece.

A conservator may be unable to solve every problem. "Sometimes the best thing to do is to (just) stabilize and preserve the artwork until technology advances enough to safely address the problem," Kerr-Allison said. For example, conservators won't touch an accidental mark made after someone dragged a pencil along an unprimed canvas.

A conservator will document the project with a written report and photographs for "protection from liability, an illustration for what we've done, and a record for the next generation," Ingalls said.

A conservator can be pricey, so your piece should be worth the investment. "Much of what you see at the Smithsonian was originally from personal collections," Kerr-Allison said, so it may pay if you feel "your personal treasures deserve as much attention as a van Gogh."