I know. Knitting in the round is faster. Purling is kinda awkward. It’s satisfying to be able to try your sweater on. And when you’re done knitting, you want to be DONE.
I hear ya, sister.
However, I prefer to WEAR garments that have been seamed - and honestly? I've come to find piece knitting easier and more satisfying - let me tell you more!
Seaming adds structure. This is a whole topic on its own, and I don’t want to get stuck here - but I do want to point out when it’s particularly critical.
Your garment is heavy - you’ve used a dense yarn, or the garment is voluminous because it’s oversized or long.
Your sweater already has a lot of stretch to it, such as in a ribbed fabric.
Your fabric is already unstructured because it is made from slippery fibers, knit with loose gauge, or has little or no structural design elements (cables, picking up and knitting, or other design elements that add tension or firm edges).
If you’re really attached to knitting your raglans in the round, there is a technique that lets you make the best of both worlds - basting your raglans. In this technique, you add a purl stitch where the seam would normally be, and then go back and ‘seam’ it out. This gives you the ease and speed of all right-side knitting and the structure of a seam. I haven’t tried this technique yet, but it’s high on my list!
“Knit in the round until you reach the underarms - then split and work the front and back separately”. Sounds like you’ll be making two swatches - one for working flat and one for working in the round. Why? Working a purl stitch uses more yarn than working a knit stitch, fundamentally changing the fabric - most knitters experience a gauge change. If you’re knitting flat, there’s no agonizing over a gauge change.
Knitting sleeves in the round sucks
I said what I said! Knit 'em flat and seam, it’s faster and easier.
First, putting a sleeve on double-pointed needles in your project bag and tossing it in your project bag is a sure recipe for dropped stitches.
Second - components are smaller than whole sweaters, and just inherently easier to pack and carry! Piece knitting is also better for folks who cope with wrist pain and tendinitis, the light pieces create much less strain.
Need to adjust one section? Limit the pain
I recently finished a lovely collar bind-off and slipped my sweater on, only to find that I wanted to drop the neckline several inches. Luckily, it was seamed. I backed a few inches of seaming out of the front raglans, ripped back the front, and reknit the neckline. Including the math, the knitting, and the seaming, the whole re-configuration took just an hour.
Pieces are better for distracted or frequently interrupted knitters
Working one piece at a time means you’re normally just working one set of instructions at a time (it’s simpler), and you’re finishing rows faster. If you want to squeeze in some knitting while you fill your gas tank or wait on hold, you’ll be much more able to put a few rows in on your sleeve cap shaping than you would be able to put in a few rows of short row shaping to create a seamless cap.
Alternating skeins in the round is fussy and high stakes
I love working with hand-dyed, tonal, and speckled yarns. Those yarns look best alternated. You can alternate skeins in the round, but it’s fussy, and if you twist the yarn the wrong way it makes a hole. A very visible hole (ask me how I know). If you’re knitting flat, simply carry the yarn up the side of your piece.
I talk about the advantages of knitting flat specifically for beginning knitters in this post.
Curious about basting your seams? Sister Mountain talks about this over on her blog - check it out!
So you're sold on trying a seamed garment, but you've never done it before? Or you're not happy with your technique? Check out this tutorial from Brooklyn Tweed. I find it helpful to approach my seaming with a fresh and peaceful workspace and the same mindful attitude I need for perfecting my hand quilting skills.
Amy Herzog's The Ultimate Sweater Book has a GREAT discussion of structure and fabric (and is also a great resource for designers and knitters who want a perfect fit, AND has some stunning patterns!).