There are companies that will make holes in woven fabrics literally disappear, but they're not cheap. If you have the time, try making a patch for the hole yourself.

Darning a sweater is basically weaving new thread or yarn of the same color of the item back and forth horizontally and vertically to close the hole. This is done on the wrong side of the fabric to better hide it.

1. Sew It Up
The elbows and shoulders of a sweater take a lot of wear, making them vulnerable to damage. Larger holes can be fixed with patchwork or by using a knitting technique called darning. Darning can be time consuming and challenging for those without much hand sewing experience but mending is one of the best ways to give your favorite sweater a second life.

There are professional menders that specialize in fixing woven fabrics and making holes literally vanish but this is not a cheap option. A better and less expensive alternative is to learn how to mend knitwear yourself. It’s a simple process and once you get the hang of it, the hole will disappear to look like a little woven patch. You’ll just need a needle and yarn that matches your garment. Several knitting blogs including VeryPink Knits, River City Yarns, and KNITFreedom have excellent videos with clear photos of mending techniques. This book is available at Better World Books a leading socially conscious online bookstore with low prices, free shipping, and a 100% money back guarantee.

2. Press a Patch
You can strengthen a worn down area and hide it with a patch of lightweight fabric like pearl cotton or yarn that is the same color as the sweater. This technique takes longer and is more difficult to sew, but it will look better in the long run.

You must first iron the patch to adhere it to the garment. Choose a low heat so you don’t accidentally burn the woven fabric or discolor your sweater, and make sure you are pressing on the back of the patch (not directly over the design).

Next, take a flat ladder stitch around the edge of the patch and into the surrounding stitches, extending your thread a full inch beyond each side of the hole. Repeat this process, extending your stitching up and down the row of stitches and covering the patch of fabric, until you are a centimeter past the edge of the hole. Then, stitch across the top of the patch a few times to anchor it.

3. Cover It Up
If your sweater has multiple holes that are caused by moths, it's time to toss it. Clothes moth larvae are notorious for chewing through woolen knit sweaters, and once they've destroyed a large enough portion of the garment, it's probably best to just throw it away.

But if the damage is less severe, it may be possible to repair your sweater with a little darning or embroidery floss. Thread a needle with matching thread (or as close as you can get) and carefully stitch around the hole, making sure to pull the edges of the hole together. If you do this correctly, you won't be able to see the stitches from the outside of the sweater.

You can also cover a large hole with a fabric patch or reshape the piece of the garment that has the hole in it. If the hole is in the elbow of your sweater, for example, you might remake the sleeve into short sleeves.

4. Replace It
If your sweater has a large hole, or if you want to make it more noticeable less likely to happen in the future, consider using a patch. A patch covers the hole, so if it goes wrong you only need to sew it up again.

The patch technique works for small holes as well, and it's an easy way to keep a knit in good shape. Just be sure to use a yarn color that matches the garment, and leave a tail whenever you start or end a piece of stitching.

While it's tempting to toss a moth-wrecked sweater, mending the damage will save you money and keep your favorite sweater in your wardrobe for years to come. And that's worth more than just a few minutes of your time. If you're not the DIY type, there are several trusted knitting repair shops in cities across the country that can take on your moth-ravaged woollen garments.