The darning on the left isn't a terrible mending job, but if I'd used the same color yarn, it would be less visible. On the mending below, which is the foot of the same sock, you have to kind of squint to see where the fabric is different.
But you can darn just about anything made of any kind of fabric and the method is more or less the same. I tend to use it for holes that are about an inch in diameter (2.5cm) or smaller. That's about the size of a US quarter. Any larger than that and I put a patch on it. When you can match the color of the thread to the ground fabric, it's great for places where you want your mending to be as inconspicuous as possible. I drew a little diagram here, but I've also found some very nice drawings from the DMC Encyclopedia of Needlework, which is free via Project Gutenberg and in the public domain.
Darning is just weaving on a teeny tiny scale so that you can replace the missing fabric. The drawing above shows how to lay down the warp threads. Ideally, you can match the weight of the fabric by using the same size thread as what the ground fabric is made from and replace the warp thread-for-thread. That's not always possible or desirable, but I will say that if the darning and the ground fabric are too mismatched, you risk further damage to the garment and/or ruining your darning job.
To the right, you can see how to weave the weft and it can be as easy as under, over, under, over, like when you did paper weaving in grade school, only tiny.
Here's one that I've done in different colors for the warp and weft, which ends up with kind of a neat effect.
You can use any weaving pattern on a darn, which is useful if it's going to be visible and you want to show off your mad darning skills.
This week, I grabbed the left shoe of a pair of canvas shoes that I'd gotten new on sale for less than ten bucks several years ago. The holes were about the right size, so I thought I'd try out damask darning on the bigger hole.
I like these, they're comfy and only the left shoe had worn out in those two places (my shoes always wear out on the left in the same places). The right is in pretty good shape, so I thought it was a good candidate for mending. For most of my darning I use plain ol' DMC stranded cotton embroidery thread. It's cheap and easy to come by in lots of colors and I have a whole heap of it laying around.
And that's it for the Month of Mending this year! I hope you're encouraged to fix it when you can instead of throwing it out so that you can show off your awesome hipster activist art.
Next month in our year-long-along-of-alongs will be February is for Finishing. This year, I'm going to be more honest than usual about all the projects I have going on. We can think of it as therapy for DaVinci Disorder.
Happy mending and see you in February!