How old paintings are professionally restored

• Sara Drew is a conservator at Center Art Studio in New York City.
• She showed us how she cleans and restores a 180-year-old painting of English opera singer Lucia Elizabeth Vestris.
• The painting has paint loss, thick layers of dirt and tobacco smoke, and physical tears.

The following is a transcript of the video.

Sara Drew: My name is Sarah Drew, and I work as an art conservator at Center Art Studio in New York City. This is a portrait of Madame Vestris. The first thing we do is inspect the painting with a blacklight to understand what all the issues are.

So you see the purple light, and then you see the kinda, like, the greenish light? That indicates to us that there's, like a heavy, thick old varnish on that surface. If there wasn't that, you would just see pure purple.

You couldn't make out any sort of contrast or light in the background. The ornament and the details on her clothes were completely obscured. There was something on her head; we weren't sure if it was a hat or if it was hair.

When you're running the Q-tip over the painting, it can be quite black or quite orange or yellow depending on what you're taking off. Her skin was beautiful. It was bright, it had brushstrokes, color contrast, light.

The first step of removing the painting from the stretcher is to take out all of the tacks that are holding the sides of the canvas onto the stretcher. I'll save them and I'm gonna reuse them later.

You can see me using a knife to separate the lining canvas fully from the structure. Now comes the riskiest part, separating the painting from the stretcher. You want to be very careful because if the paint is not stable, you risk bending the painting and causing flaking or further damage. I need to cut strips of linen and attach them to the canvas so that I can then put the whole piece back together again.

I cut strips of BEVA, which is a conservator's adhesive. I then put the painting on the stretcher and use tacks to reattach the painting to its stretcher Then I filled, with a water based putty, areas of damage.

And I overfill the areas a little bit, and then I come back in with a damp cotton swab and clean up those fills.

Also, the original canvas doesn't extend quite to the edges of the stretcher so I need to go and fill about a quarter of an inch around the entire perimeter of the painting. Once the painting is filled, I will begin the retouching process.

I will use a paint that is specifically designed for conservation work. You're just trying to match the color to the color that the artist put there, and making sure that you're not painting over any of that original paint. There's two types of inpainting that I will do here. The first is inpainting over the fills that I just made. The second is inpainting the background. And this is the area that was previously overcleaned by the other restorer.

It's really important to use a conservation paint that dissolves in a solvent that is different than the original paint. And this allows our paint to be completely reversible. We could easily use that solvent to take off our paint and then the original paint would be unaffected.

Then I will be ready for varnish. We use a completely reversible non-yellowing varnish. I need to wipe off the surface of the painting with just a cloth because, like anything, it can accumulate little particles of dust, little hairs. I wanna make sure that that surface is as clean as possible. So once I wipe it off, I will brush on the varnish.

When you brush on the varnish, those fills, that inpainting, it all kind of blends cohesively into the background and into the surface of the painting and it just looks complete. And the restoration is complete.