With the wool I dyed with dandelions last year, I made a pair of knitted garters. When I do garters, I knit them in the round on two needles. It’s like double knit, except that you just move the purl stitches over to the other needle instead of actually purling them. Knitting Women has an overview of the technique.
Why do I knit garters like this? The short answer: The Attack Laurel told me to. Long answer: She briefly mentions knitted garters on her Extreme Costuming page. I wanted to make some, so I asked her about them, including how fine gauge the ones she’d seen were. She emailed me back and mentioned the knitted garters at the MFA, which she said were probably done on 0000 or 00000 needles, knit in the round on two needles. If you look at the picture, you can see that the pattern is on both sides, which definitely suggests to me that this was the technique used. (If they were knit flat, you’d have a weird looking reverse side, which would be the wrong side of the colorwork.) They could also have been knit in the round the usual way, with 4 or 5 needles, but I think that would be really awkward for something this narrow.
The garters I made are not nearly as fancy or as fine gauge, although I would like to do fancy colorwork garters at some point.