• X-ray machines scan large artworks for cracks in the same way that they look under your skin for broken bones.
• Needles are used in biopsy fashion to pull tiny chips from paintings for examining under a microscope.
• Infrared cameras, developed to enhance night vision during the Korean War, look beneath painted surfaces to see the underdrawings that masters used to plan and prepare their paintings.

All these tools help art conservators examine, understand, and care for important works of art.

• Find a painting you like in a book about art. Pretend you are a conservator. What would like to know about this piece of art? How might technology help you?

The restoration of the Sistine Chapel serves as a fine example of art conservation and restoration. Renaissance artist Michelangelo lay on his back for five years to fill the chapel's ceiling with paintings that since became world famous. For years, many people thought Michelangelo had used dreary, somber colors. But in one of the most public undertakings in art conservation history, conservators cleaned the ceiling with gentle solvents and uncovered images full of vibrant, glorious color.

The Benefits of Cross-Training
Michelangelo's work in the Sistine Chapel was victim to the same stresses that affect every work of art on display: dirt, heat, humidity, and light. At some point in the life of almost every painting, there comes a time to call an art conservator for help. But art conservation is not just a matter of using technology to clean up; it can also call for considerable artistic skill. At the Straus Center for Conservation, senior curator Teri Hensick uses a paintbrush as much as she uses a microscope. Like her, many art conservators have backgrounds in the sciences — physics, chemistry, and geology — as well as in studio art.

In the first video clip on the right, you'll see Hensick in the process of restoring a painting by a seventeenth-century French artist named Jacques Stella. Specifically, Hensick is at the stage where she is "inpainting", that is, she is repairing the layer where the paint has been damaged. Previously she has spent months looking through a microscope and scraping away bad repairs done earlier in the painting's life. (Often, part of the art conservator's task is to undo poor work done in the past.)

One of the most interesting parts of this restoration came early, when Hensick retrieved a sample of the painting. A needle stuck into a crack in the surface extracted a tiny fragment. Hensick encased it in a polyester resin and examined it under the microscope. What she learned was that while the surface of the painting had large areas of gray, the artist had, in fact, used a red ground, or initial, layer. It is the red you can't see that gives this large painting a warm, lighthearted cast.

• Why do you think it's an advantage to see a cross section of a painting?

Seeing beyond Surfaces
The Straus Center has been a leader in using infrared technology to explore beneath painted surfaces and to learn how the old masters achieved their effects. Infrared photography uses a type of light not visible to the human eye. Henry Lie, the center's director, says that this technology is ideal for art because of its ability "to let us look through all those layers of paint and see things no one has ever seen before."

This technology has changed how art historians work, Lie says. Having access to these "underdrawings" — the original sketches by the artist — makes it easier to determine the painter when there is a question of authorship. Infrared is also used to help detect forgeries and copies.  

• Tour an interactive exhibit that uses this technology.

Like many in this profession, he does not ply his craft in a museum or an institution but in his home studio, where he restores paintings for customers. His approaches are not as high tech as those of his museum counterparts. For Tokatlyan, conserving art is simply a labor of love. You'll find an interview with Tokatlyan in the video clips to the right.

Preserving the Future
Whether through advanced technology or more homespun methods, the work of art conservators plays an important role in the life of our culture. In the case of the Sistine Chapel, it meant uncovering the vivid color of Michelangelo's original design; in the case of the Star-Spangled Banner, it means preventing a physical piece of history from crumbling away. For art conservators, it's not about stopping time, but about providing a buffer against its relentless effects, and preserving the future — as much as the past — of our cultural artifacts.