Image: Knitwear

Q:My mother recently gave me my baby sweater from 1959. Unfortunately, it is badly stained. I do not know the origin of the stain. I want to clean the sweater but I'm afraid of damaging it further. There are already small holes where the sweater appears to be disintegrating from the stain. I think the yarn is wool. Do you have any suggestions for restoring my baby sweater?

A: Given the high sentimental value of your baby sweater, you might want to start by contacting a professional conservator who specialises in treatment of textiles. Conservators typically do a preliminary analysis, often at no cost, and then give you a range of treatment options, with estimated prices. You then can make an informed decision about how to proceed. One way to find a qualified conservator is to use the "find a conservator" service on the American Institute for Conservation of Historic and Artistic Works website (conservation-us.org). You can search by Zip code and specialty - "textiles," in your case. Then scan the "services" section of the listings to find conservators who do treatment and are in private practice rather than on the staff of a museum.

Julia Brennan, who is listed on that service and owns Caring for Textiles, a conservation service, looked at the picture you sent. She thinks the holes could be moth damage, which often occurs in wool sweaters that are stored for long periods. But she would analyse the fibers before doing any work, because cotton, wool and acrylic are all possibilities for baby sweaters of this vintage. DuPont developed the first acrylic fibers in the 1940s and trademarked them under the name Orlon, but the fibers were not widely used until the 1950s.

"Stains are stains and often very difficult to get out," she cautioned in an email. That is even more so in knit and crocheted items, she said, because the stains are often embedded in the twisted yarn. Stain removal is especially tricky when there is nearby embroidery, because the colors might run and the embroidery threads are delicate.

She always begins by examining the yarn to see if the stain is on the surface, so if you decide to try to clean the sweater on your own, that should be your first step, too. Sometimes it's possible to brush or scoop off a spill, using a soft brush or a spatula. If that's not sufficient or if the stains are embedded, the next step is a careful washing. Before you begin, trace the outline of the sweater so you will know later how to shape the knit to the same dimensions.

For soap, Brennan suggests using a little clear hand dishwashing liquid. "I cannot recommend using any commercial detergents as they have so many additives, and whiteners and all sorts of stuff in them," she said. Bleach - whether it contains chlorine or is a chlorine-free oxygen bleach -- is too harsh, she said.

With wool, it's important to be gentle and use cool water because scrubbing the fibers and using hot water can cause the wool to "felt," or get thick and matted. Wash by hand and let the sweater soak for a bit. Periodically swish it around to work the water through. Then rinse several times. Instead of wringing out the excess water, place the sweater on a towel, roll it up and press down on the roll. Unwrap and set the sweater on a dry towel.

Then "block" the sweater, which means you arrange it, on the towel, to the original shape, even if that means gently stretching the yarn a bit or squishing the knitted rows closer together. The drawing you made might come in handy. "My mother's generation knew all this, as they carefully washed their own Pringle sweater sets and scarves," Brennan said. People did not depend on dry cleaners, as many do today.

It's not necessary to remove all of the stains - they are, after all, a sign that you actually wore this sweater. But if they are still vivid enough to bug you, Brennan suggests recleaning the worst areas, again with hand dishwashing liquid in water. Rub gently and rinse. If the stain lessens, repeat the process until you see no more improvement.

As for the holes, you can leave them or have them mended. Brennan suggests contacting Jennifer Lindsay, a master knitter in Washington, who can often reknit damaged areas so skillfully that the repairs are almost unnoticeable.

- The Washington Post