A real cashmere sweater can last several decades, as long as it is good quality and cared for, according to Knit Alteration & Design. Repairing a cashmere sweater translates to making it fluffy, clean and fresh. Cashmere sweaters can be cleaned and repaired right at home without professional care, as long as directions are carefully followed. Cashmere should be handled extra gently, especially older cashmere. Real cashmere should not be chemically treated with bleach or other products since it will never yellow or fade.
Cleaning your sweater
Clean your cashmere sweater either by dry cleaning, which can be done professionally or at home using a dry cleaning kit, or by hand washing. For stains, the better choice is to dry clean. Take the sweater to a dry cleaner's or purchase a dry cleaning kit. If using the kit, place your sweater in the dry cleaning bag and include a dry cleaning wipe in the bag. Place the bag into your dryer and dry for about 20 to 30 minutes.
To hand wash, prepare a large bowl, basin or the sink. Pour in warm water mixed with a gentle cleanser such as baby shampoo or Ivory flakes until the water is sudsy. Soak the sweater for about 5 minutes. Then, using your hands, squeeze the sweater gently so that the suds soak through the fibers. Rinse in warm water until the suds are gone, squishing the sweater. Do not wring.
Place the wet cashmere sweater onto a towel and roll it around in the towel. This removes excess water and makes it dry faster. Lay the sweater flat on a dry towel. Arrange it into shape gently since wet cashmere may stretch out and lose shape. An important thing to remember is that your cashmere sweater will stay the way it's arranged to dry.
Once it's dry, place the sweater inside out into a large lingerie bag or pillow case so that it has enough room to tumble. Place it into a dryer at a cool temperature and dry for a few minutes. This will restore the cashmere fibers and give them new life. Your cashmere sweater should look restored and new.
Re-weaving your sweater
Find the extra yarn that came with your sweater, if you have it. If not, get yarn in a color, thickness and texture as close to the cashmere sweater yarn as possible. If your sweater has holes, it will need to be re-weaved. You can do this by yourself or bring your sweater to a professional who restores or alters cashmere sweaters.
Gently stretch out the cashmere fibers around the hole. Avoid making the hole bigger by not pulling too hard. If the hole is small or a simple snag, the fibers might return back into place, hiding the hole. If they do not, you may have to do some sewing.
Lay the cashmere sweater flat and locate the hole. Insert and close a safety pin into each open stitch on top of the hole as well as on the bottom of the hole.
Cut a piece of yarn about 2 feet long using sharp scissors so the end does not fray. Insert it through the eye of a large needle but do not tie it at the end or double it.
Push the tip of the needle through the closed stitch to the left of the top row of open stitches. Pull the yarn all the way through but leave an inch of it hanging on the inside of the sweater. Tie a knot around the closed stitch using the hanging yarn on the inside of the sweater. Push the needle through the first open stitch farthest to the left on the bottom of the hole and pull the yarn all the way through.
Insert the needle through the top stitch, which is just above that stitch and pull it through all the way. Repeat for the rest of the top and bottom stitches, alternating between the two rows of stitches. Weave the yarn through each open stitch.
When finished, insert the needle through the stitch to the left of the stitches that used to be open and tie a knot inside the sweater around that stitch. Cut off any remaining yarn.