If you pay any attention to trends in the crochet word, you've probably encountered at least one pattern for a Two Hexagon Sweater. The basic premise is that you make two hexagons that very much do not lie flat, and each hexagon roughly folds into the shape of half a sweater--an L shape. Then you sew the hexagons together along one side, which creates a seam down the center back, and along one side of the L on each hexagon (the tops of the sleeves), and you have a blocky sweater.
A very famous concept in knitting is Elizabeth Zimmerman's Baby Surprise Jacket. The Two Hexagon Sweater, once the center back seam has been sewn, is the same shape, making it a simplification of that concept. Many of the Two Hexagon Sweater patterns out there also involve a fair amount of finishing work. While the concept, whether knitted or crocheted, is sound, the proportions don't quite work with the shape of the human body. Because all the sides of the hexagons are the same length, you end up with sleeves that are the same circumference as half the bust measurement and an armpit-to-waist length equal to the sleeve length. Most patterns either get around that by using the pattern as a short sleeved shrug or add considerable length to the hem and sleeves, along with some sleeve shaping that doesn't look quite right, after all the assembly is done. The shapes involved also limit the neck shape to a basic lapel shape if the sweater is kept as a cardigan, or a boatneck or henley neckline if a center seam is added to the center of the front.
Naturally, I set out to see if I could play around with the hexagons to make something that was a little more tailored, and I succeeded.
While there are some patterns out there for knitted versions of this sweater, most of the crocheted ones make the hexagons as variations on the classic granny square. The increase points at the corners of a granny square create the impression of four right triangles (one of the angles in each triangle is a right--90 degree--angle), with the right angles of each triangle meeting in the center of the square, which is what happens if you draw an X in a square, with each line end in a corner. The hexagons for the Two Hexagon Sweater take a granny square and add two more right triangles to each of them, giving you a hexagon that will not lay flat. Instead, it folds into that L shape I mentioned.
I decided to play with this idea by making a baby sweater. Not only are baby sweaters small and quick and easy to make, but babies have body proportions that are closer to the proportions of the Two Hexagon Sweater than adult body proportions, meaning I'd need to do less tweaking to see if my idea worked. For those who are interested, I used Mandala Sequins, by Lion Brand, which I bought for a song on clearance. It's a self-striping, light worsted weight acrylic, and I like how it works up on a 4.5 mm hook, which is midway between a G and H in American sizes.
The first thing I wanted to do was add sleeve shaping. If you look at pretty much any long-sleeved shirt or sweater from a store, you'll notice that the armholes are almost always bigger around than the cuffs, and the change in measurement happens along the underside of the sleeve. One side of each hexagon forms the cuff, so I picked which side that would be and then did a double decrease every couple of rows in the middle of that side. That modification worked really well, and I was very happy with how it turned out.`
The second thing I wanted was to create a V-neck for the cardigan. Part of how a granny square usually works is that you add 4 new stitches at each corner. That same method of increasing is used in the hexagons for this sweater...mostly. The side that creates the front of the sweater is the second side from the cuff on both hexagons.
I didn't add any neck shaping for the first few rounds, because the distance across the neck on most sweaters is about a third of the total measurement from shoulder to shoulder. The other two thirds are each of the shoulders. If the part that's open for the neck is too wide, the sweater won't stay on the shoulders. This is especially important on baby sweaters, since babies have very narrow shoulders.
After a few rounds, I split the relevant increase point into two increase points, creatig a Y shape with the increase lines. At the two new increase points, I only increased two stitches, meaning that my total number of stitches stayed the same as it would have if I hadn't done any neck shaping. And I lined up the increases so that the number of stitches between those two increase points increased every round. In the sample I made, When I started the neck shaping was a matter of informed guesswork. Unlike the sleeve shaping, I wasn't entirely sure how to figure out when to start it, but it mostly worked out.
As I worked, however, I realized that, while the sleeve shaping determined the cuff circumference, it was not what determined the circumference for most of the arm. In making these hexagons, the distance from the center, which is at the center of the armpit, to the edge is half the width of the sweater, or a quarter of the chest circumference. The length of the unaltered sides is also the length of the sleeves. And the sides on either side of the cuff create the bulk of the sleeves, especially along the upper part of the arm. If I didn't want bulky, boxy sleeves, I needed a shorter row gauge on those sides, not just decreases in the middle of the cuff edge.
My go-to method for crocheting adult-size garments is side-to-side construction. Years ago, I wrote a post here about adding shaping to nip in the waist of such garments by working a few inches of each row in a shorter stitch. That's exactly what I did in this concept piece to control sleeve circumference. For most of each hexagon, I alternated between rounds of double crochet and single crochet. Once I figured out that my sleeve circumference was getting too big, I stopped using double crochet on those sides and switched to single crochet only, transitioning to and from double crochet at the increase points on either side by working the first two stitches of increase as a single and half double crochet. I also switched to single crochet only for the neck edge to make sure the front neck would be the right width relative to the back neck.
If I were to play with this sweater concept again, I would change how I worked the sleeve sides from the begining to create a more uniform appearace and texture.
The other modification I made in this sample was to the waist measurement. One side of each hexagon forms half the waist. I chained 2 on the corners on either end of that side, instead of the usual chain 3. My main purpose there was to make the holes on the increase lines smaller. That meant that the "triangles" that formed either half of the waist aren't quite right triangles, creating a slightly tapered waist. However, that shaping also made the bottom of the center back seam a little wonky--scalloped almost. I can see the tapering in the picture above, although the edging took care of the weird back seam shape. I'm not sure I would do that in the future, especially for a baby sweater, but it was something to think about. However, I think increasing with fewer chain stitches, especially in the early rounds was a good idea.
Ultimately, because I avoid sewing seams, I crocheted all the seams together, and then worked around each cuff and the edge of the body of the sweater in several rounds of single crochet and then one round of light crab stitch. I also added buttonholes to one of the plackets and sewed on buttons. All in all, I think it turned out really well, especially for a first prototype that I basically improvised. Adding gradual shaping to the sleeves and a V neck are definitely doable modifications to the Two Hexagon Sweater and well worth exploring.