REAT WORKS OF ART— or even not-so-great works of art— tend to gain value over time. But they also gain coats of dirt, suffer from flaking paint, water damage, and color loss. Into this picture come Peter Fodera and Kenneth Needleman.

Fodera and Needleman are leaders of a small, largely anonymous band of professional art conservators— don't call them restorers— who take damaged works and, if you will pardon the expression, restore them to their former glory.

The artists in their studio: Roberto Figueroa, Peter Fodera and Kenneth Needleman discuss plans to conserve an American Modernist painting. PHOTO: Nancy Rica Schiff

The distinction between "restoration" and "conservation" may seem semantic, but to Needleman, it speaks to the essence of his calling. Conservators do not "restore" the appearance of a painting or work of art, Needleman says. They make visible the artist's original intent.

Thus, when a collector purchased an American-made japanned high chest built between 1712 and 1724 for $1.6 million (japanning is a style of painting meant to emulate the laquer of the far east.) his first stop was Needleman and Fodera's studio in the Garment District of Manhattan. Experts on the firm's seven person staff went to work clearing the layers of dirt that had built up on the piece obscuring the painted details below. "You can never get back to the original," Needleman explains, "but you can get to a place where you can understand the artist's original objective."

RT CONSERVATION is part science, part art. To work at the highest levels, a conservator must understand a work's history as to understand the artist's intention. He or she must also know the science of the materials that the artist worked with. Ultraviolet lights and X-rays that peek beneath the surface of a painting are part of the conservator's arsenal. He or she must know the contemporary materials and techniques that will best approximate the original work and blend in with the undamaged portions. And he or she must be detective enough to spot the tiniest blemish and to know what caused it.

The goal is to make the original visible, to "stabilize" and protect the work, of course, to make it look good. While collectors all understand the last goal, making them appreciate the subtler aspects of what a conservator does often requires some education, Fodera says.