I'm afraid this post may get a little disjointed; we're going to cover several of the little details about stranded knitting, but while they all have to do with this type of knitting, they don't necessarily have all that much to do with each other. So bear with me a bit if it seems like I'm jumping around.
Let's start with weaving in the unused strands. That's kind of a big deal, and I felt sort of bad about leaving it out of the last post, but it really was getting unwieldy already. When you weave in a float, you're catching it around the strand of the color that you make the stitch with, and it actually gets caught twice, once on either side of the stitch where you do the weaving. The gist of the method is that you wrap the unused color, then wrap the color you're using, and then unwrap the unused color, which leaves it caught by the strand of the color you're using but not pulled through to the front of the fabric. What this actually does is cause the unused strand to be wrapped around the strand you're using twice -- once before and once after the stitch just completed, in opposite directions. Exactly how you execute this varies, depending on which method you're using and which strand you're catching.
We'll take things in the same order we used for the basic method, and start with the two-handed method. If you're catching the right-hand strand, then you literally do wrap and unwrap: put the needle into the stitch, wrap the right-hand strand around it, catch the left-hand strand as you normally would, and then unwrap the right-hand strand with the opposite motion from the motion you used to wrap it, and then pull the left-hand strand through as normal. If you're catching the left-hand strand, then what you do is duck your right needle tip under it, then wrap the right-hand strand normally, and then pull the needle back out from under the left-hand strand as you pull the stitch through. The astute knitter will notice that going under the left-hand strand actually wraps it in the opposite direction from the way you normally wrap it when making a stitch. This doesn't matter, since the strand isn't forming a stitch itself and therefore orientation isn't an issue; what's important is that it's wrapped one way and then unwrapped the other, and that does happen here.
For the method with both strands in the left hand, first we need to figure out how to designate which of the two strands we're talking about. Because this terminology will come in handy later, I'm going to call the two strands the "upper" strand and the "lower" strand, with the lower strand being the one that's further to the left. I'm using this nomenclature because, if you pull your hand off to the left side, you'll see that the strand that's further to the left ends up below the other. That positioning will be important later, when we talk about yarn dominance; for now, just keep in mind that that's what I mean. To catch the lower strand, the process is similar to catching the left-hand strand in the two-handed method. Duck the right needle tip under the lower strand, then catch the upper strand normally, pulling it under the lower strand before it comes through the old stitch. Catching the upper strand is a little more complex, for two reasons. First, if you simply come under the upper strand from above, it's then nearly impossible to catch the lower strand and draw it under the upper strand; you can do it in the opposite orientation, but then you have to correct the stitch mount or work it through the back on the next row or round. Second, and a more serious obstacle, this brings the upper strand across the front of the lower strand, which tends to cause it to get pulled into the new stitch being formed, resulting in the caught strand showing on the face of the fabric. Ideally, one would like the caught strand to go behind the new stitch, being caught on either side, rather than caught across its face. The solution is more complex to describe than it is to execute: after putting the right needle tip into the stitch, you will pass it under both yarns, then from behind, you will come over the upper strand and under the lower one; this results in the upper strand passing in front of the tip, and the lower strand behind it, with the two strands crossing on either side of the tip. From there, twist the tip backwards to catch the lower strand normally and pull it through the stitch. If you have a strickfingerhut, so that the yarns are attached to your forefinger, there is an even easier means of execution: bend your forefinger down against your palm, so that the yarns are below the finger and their positions are reversed; go under the closer strand (which was the upper one) and catch the further one (which was the lower one), pull it through, and then straighten your finger out again.
For the method with two strands in the right hand, weaving is relatively simple for both strands: wrap the strand to be caught, wrap the strand to be used for the stitch, and unwrap the strand to be caught.
What if you're purling? There are generally two situations where you purl in stranded colorwork: when you're working flat on the WS of stockinette, and when you're working bi-color ribbing. Stranded colorwork pretty much isn't used with any other stitch pattern, because of how purl stitches work with different colors. If you're working flat on the WS, you're going to be stranding both yarns across the WS, which will be facing you, as well, and you may well wish to weave some of your floats; you'll follow essentially the same method that you did with the knit stitch. If you're working in bi-color ribbing, you probably won't be weaving; generally you'll use one color for the knits, the other for the purls, and the ribs won't be wide enough to make it necessary to weave. If you do feel like weaving is necessary, you've got a bit of an issue; with most purling methods, the yarn is in front of the fabric, while the yarn you'd like to weave is behind it. There are two choices: either you can use the Norwegian purling method, where the yarn is carried behind the work while purling, and therefore you can duck under and out of the yarn you wish to weave just as you would while knitting (but only if you carry the yarn in your left hand -- this method just doesn't work where the yarn and the working needle are in the same hand); or you can take the yarn back, twist the two strands together manually, and then bring the yarn forward again and resume purling. If there's another way to handle it, I haven't been able to work it out, but I'd love to hear about it if someone's got one.
Actually, I lied about the two situations, because there's one more, although few patterns call for it explicitly: Meg Swansen's "purl when you can" method for making a non-rolling edge. This is a method for distributing enough purl stitches within a section of stockinette to make it lie flat, while not disrupting the pattern with the little dashes that you get when purling into a different color. This method is sort of the opposite side of the coin from the method of working the first row of a stripe in ribbing as stockinette. What you do is that during the first two inches or so of the fabric, any time you're working a stitch into a stitch of the same color, instead of knitting it, you purl it; because the stitch below is the same color, the color dashes blend in, and if you can work enough of these in there, you'll create a balanced fabric that doesn't roll up, without having to start your garment with ribbing. Take "any time" with a grain of salt; if you've got a long segment of one color, you may want to make only part of the stitches purls, so you don't end up with a segment of reverse stockinette wanting to curl the opposite direction. If you're using this method, though, weaving while purling won't come up; if you've got a long enough strip of one color that you'd want to weave in a float, take the yarn to the back and knit a stitch with the float woven in, and then come back forward to purl again if you want to.
So, that's weaving. And a couple of paragraphs ago, I alluded to bi-color ribbing, so let's talk about that next. Bi-color ribbing, which is also called "corrugated" ribbing because it rather resembles corrugated cardboard, is a very popular way to begin colorwork garments; it's usually a 1x1 or 2x2 ribbing, and is done by making all the knits one color, and all the purls another. Because of the way the stranding interacts with the peaks and valleys of the ribbing, it's less elastic than regular ribbing (but still slightly more elastic than stranded stockinette), and the purls are more prominent. For an example of corrugated ribbing, take a look at my Melonhead watermelon hat pattern (or the thumbnail on the sidebar of this blog); in the pictures, the knits are in dark green and the purls in pale green. That was actually an error on my part -- because the purls are in a different color than the cast-on row, I have color dashes at the bases of those columns. I corrected that as I wrote the pattern up, and if you follow the pattern instructions, you'll have pale green knit columns (which will flow more smoothly into the solid pale-green stripe above, also), and dark green purls to match the cast-on edge. Learn from my error -- for corrugated ribbing, cast on in the purl color, not the knit color. (Edit: As an alternative, cast on in color A, and do the first round as "p2in A, k2 in B" and then switch to "k2 in A, p2 in B"; reversing the rib in this way will give you an edge that's still stretchy but doesn't have color dashes in it -- you can see the effect if you look very closely, but it's subtle.) Aside from that, corrugated ribbing is done pretty much just like single-color ribbing, with one exception: For those who carry both yarns in the left hand, you will find that it's a bit of a pain in the neck to move the purl yarn forward while keeping the knit yarn in the back, but this is a perfect place to employ the Norwegian purling method, where the right needle ducks behind the yarn instead of the yarn moving forward.
What about for those who carry one yarn in each hand? Sorry, but your purl yarn is generally going to be in your right hand, which means this purling method is generally unavailable to you. Why is it in your right hand? Because of yarn dominance. In stranded knitting, as the yarns travel along behind the work, one strand will be below the other, and that strand will be slightly more prominent, its stitches just a fraction larger, than the stitches of the other strand; as you can see if you draw the strands of yarn along the back of the work, it's the strand further to the left that's dominant, which means it's the left-hand strand for two-handed knitters, and because the knit stitches are usually the ones which should dominate in corrugated ribbing, the right hand needs to carry the purl strand. To elaborate beyond the case of corrugated ribbing, generally the foreground, or pattern, color is the one that should be in the dominant position, and the background color in the subordinate position. For knitters who carry both yarns in the left hand, the dominant position is the one closest to the body, which we designated as the "lower" yarn earlier (and now you see why!), in the discussion about weaving; for those who carry both strands in the right hand, the dominant position is the one further from the body -- this can be a little hard to visualize, but if you rotate the hand around so that the yarn is drawn across the back of the work to the left, in the direction of knitting, you can see that the strands rotate around so that the further one becomes the one furthest to the left and the one that's on the bottom in relation to the direction of knitting. Yarn dominance is subtle, and the differences it causes are miniscule; as a very nice example, look at this sample from Nona. You can see how the orange pattern color pops more in the lower sample, where it's dominant, than in the top where it's subordinate, but the subordinate pattern is still nice. It would be just fine -- as long as the entire item was worked in this manner. If the color is allowed to switch between being dominant and being subordinate, the difference can be glaring.
Now, we've talked a whole lot about two strands. What happens when you've got more than two? This actually doesn't happen in traditional Fair Isle -- one of its characteristics is that there are only two strands on any given row, although frequently both the background color and the foreground color will change from row to row, which can certainly give the impression of more complexity than a mere two strands would suggest. But it does happen in some of the Scandinavian patterns, and there's also no reason you can't create your own stranded knitting patterns, in which you might well wish you use more than two colors per row, so it certainly would be nice if you knew how to manage that. All you have to do, though, is a modification of the two-stranded styles. You can carry three or more colors in the same hand -- and some of the strickfingerhuts for left-hand carrying have places for three or four strands -- or you can carry two colors in one hand, and one in the other, or even two in each hand if you're working with four. What you do need to keep in mind, when deciding which color you're going to carry where, is that yarn dominance will still apply, with the lowest yarn dominating over the next, and that one dominating over the one above; pay attention to this, and be sure you're consistent throughout the work.
When we talked about intarsia in the round, we discussed the semi-stranded "festive method" as one of the options, and I promised to come back to this and talk about how you handle the various stitches when you've got some of the background color within the motif color, rather than having a solid block of the motif. As a reminder, when working a motif in color B on a background of color A, festive knitting works like this: on the first round, you work up to the edge of the motif in color A, switch to B and knit the motif stitches, stranding A behind, and then switch back to A and knit the remainder of the round; on the second round, you work to the edge of the motif with A, slip all the stitches of B, and then twist the colors together and work in the opposite direction, working the stitches of B, and then return to your original direction and slip all the stitches of B again, and then resume knitting the rest of the round with A. If your motif includes some intermediate stitches of A, you modify that like so: on the first round, you work as before, stranding A behind B, except that any stitches that should be color A are worked in color A within the motif; on the second round, you work to the edge of the motif with color A, then slip the stitches of color B, but go ahead and work the color A stitches, and then when you work back in the opposite direction, you work the color B stitches but slip the color A stitches, and as you return to the original direction of knitting, you slip all the stitches within the motif, and resume working with the strand of color A at the left edge of the motif.
The final topic I'm going to cover is steeks. Steeks are extra stitches, which some languages refer to as "bridge" stitches, put in to connect what would otherwise be two separate portions of knitting, so that a piece can be knitted in the round instead of flat; steeking is both the process of putting these stitches in, and the process of cutting through them later to separate those portions, so that the item can be finished and worn. Steeks are commonly used at armholes, at the front of cardigans, and at the neck opening, especially for v-necks. Steeks are very commonly found hand-in hand with stranded knitting, for a variety of reasons -- working in the round for the entire garment, rather than only up to the armholes, is particularly desirable when you're managing multiple strands, but also the yarns traditionally used in the areas where stranded knitting developed tend to be "sticky" types of wool, in which the fibers readily adhere to each other, which makes steeking easier to do, and the close weave of the stitches helps lock them together, which means that this method works better with stranded fabric than it does with a single color fabric (although it is possible to steek such fabrics); neither is a necessary part of the other, but they're often close companions, which is why I decided I needed to say a bit about them.
Typically steeks are worked by casting on the extra stitches at the point where the opening should begin (this would be the cast-on row for cardigan fronts, but a point in the middle of the knitting for armholes and neck openings), and then working these stitches in alternating colors, producing either stripes or checks; when the steeked area is complete, the stitches are bound off, secured in some fashion if desired, and then cut vertically to separate the portions of the garment. I'm not going to get into the methods of securing steeks; that was dealt with very competently in Eunny Jang's wonderful Steek Chronicles, which are absolutely recommended reading (and Eunny also has a great article about steeks, and a wonderful stranded sweater project, with steeks, in the Winter 2006 issue of Interweave Knits, which is the current issue as this is being written). Steeks scare a lot of people half to death, with some reason (cutting! your! knitting! eep!), but I encourage you to try them -- with some caveats. First, make proper yarn choices, especially for your first steeking experience. Steeked garments originate, and the technique is designed, for use with wool yarns that felt easily, so that slight felting sticks the stitches together, and over time the facings become firmly locked in place (as do the floats in the rest of your colorwork). It doesn't work as well with slicker yarns, and there comes a point where a yarn is just plain unsuitable for the task; for instance, I wouldn't even make the attempt in mercerized cotton. Select a substantial wool, probably not merino and not superwash, for your first project, and the whole process will be a much more enjoyable one. Second, give it a try on something that doesn't matter so much, like a swatch made just for the purpose, rather than a sweater you've spent 65 hours knitting so far. See how your yarn is going to behave, and evaluate the choices you made for if and how to secure your steek; this will make the eventual cut that does matter much less nerve-wracking. Third, one of the things that distresses people about steeked garments is that, because the armholes and so forth are steeked shut, you can't try the garment on until after that cut is made, and at that point it's too late to frog. This is certainly true, and it can't be totally alleviated, but there is one thing you can do to lessen the possibility of disaster, and that is to measure, and measure honestly. You've heard the saying, "Measure twice, cut once," with respect to carpentry, right? It's even more true with steeked knitting. Measure the garment, without stretching or scrunching, before you cut into it, and compare those numbers to reality -- if you suffer from knitter's denial about the size your garments really are, this is the time to get over it. But it's also the time to trust yourself -- if a 40" sweater is just what you need, and your measurements tell you that this piece of knitted fabric is going to be 40" as soon as you cut that v-neck open, then get those scissors and get to it. It's going to be worth it -- this is one of the techniques that get you admiring looks from your fellow knitters, who really know which things only look impressive, and which actually are.
That wraps up this topic, but I'll leave you with a couple of additional fun resources: First, the Knitting Beyond the Hebrides web site, home of the KBTH mailing list; this list focuses on traditional knitting, such as Fair Isle and Aran knitting, and the work of designers inspired by those traditional forms, and the website contains extensive galleries of the members' knitting, and resources to additional information elsewhere on the web. Second, a resource that I hadn't previously mentioned in the course of this series is Nanette Blanchard's blog, Knitting in Color, and her book Stranded Color Knitting, which is available through her website, and is a marvelous piece of work (and her profits go to rabbit rescue!); the whole blog is seeded with gems of marvelous information, but some of particular interest to those wanting to learn more about this particular topic are collected here, and I'd like to particularly call to your attention her two posts about the difference between Fair Isle and other stranded knitting, which are just a goldmine.