I’ve gotten some great suggestions in comments, twitter, and email – thank you all! You’ve helped to narrow down my options quite a bit. I’m definitely leaning towards a pullover sweater in a 9-12 month size, which should fit the twins very nicely just as they come into their first winter. Here are the four finalist patterns, in no particular order:
Henry’s Sweater from the Spring 2010 issue of Petite Purls. The designer says the pattern is “boy-ish”; I don’t think it would look too out of place on a baby girl. The yarn called for is an aran-weight, just slightly heavier than worsted, but I think worsted would work out just fine. The babies are likely to be small; between my sister-in-law’s being a very small person to begin with, and twins tending towards the small side anyway, smallish sweaters will be all right.
The Childhood Remake Sweater is designed to be knit with two strands of a light DK yarn held together; I think one strand of worsted weight should match that just fine. The recommended gauge is 17 stitches to 10 cm – that’s about right, right? I really like the solid colour of the body combined with the stripes over the shoulders.
From the Yarniad, the Candlestick Sweater looks easy enough to make, and the stripes on the sleeves are just too cute. Knit in a worsted-weight yarn, it should be a fairly quick knit. The stripe on the sleeve gives quite a few options for a matching-but-not-matching second sweater, too.
Last but not least, the Telemark Pullover (Ravelry link). While the design is entirely a solid colour, some of the projects that other knitters have worked up show a wide variety of stripes to choose from. Telemark, the recommended yarn, isn’t superwash – but KnitPicks has other sport-weight yarn that is, like Stroll. On the other hand, knitting a DK-weight sweater might take a little too long for my short deadlines.
There are a couple of important qualifications to these sweaters:
1. They must be quick and easy knits. Nothing in a fingering weight yarn here. The kids will only get to wear these sweaters for a few months at most, so there’s no point in going super-fine or fancy. And whatever yarn I choose has to be superwash, so my sister-in-law doesn’t have to worry about tossing them in the laundry.
2. I have to like the pattern enough to knit it twice. I do this with socks all the time, so I’m not too concerned about actually making the second sweater, but I’ve knit some sock patterns that I’ve sworn off forever (I’m looking at you, Pomatomus) and I don’t want that to happen with these sweaters.
3. They have to be cute, of course, and the pattern has to be such that I can knit the second sweater in swapped colours to the first. If I work on other baby-clothes first, I can probably hold out on starting these sweaters until my brother and sister-in-law announce the sexes of their babies. Honestly, though, I think standard pastel baby colours for clothing are boring, so the sexes really won’t matter at all when it comes to my colour choices. I’m considering a rich brown, or hunter green, or deep orange. Maybe a rusty red or a teal blue. Sea green is one of my favourites, or a sunny gold stripe might add a nice touch.
I might end up having to flip a coin to decide!