|BlueSand by La Maison Rililie|
1. Top-down sweaters allow you to try on for fit as you go.
2. Top-down sweaters allow you to adjust for fit, as well as arm and body lengths, while knitting is in progress.
3. Top-down sweaters generally have very few seams.
4. Top-down sweaters generally have less finishing. This is because of the lack of seams and resulting yarn ends to weave in.
Good reasons, all, especially if one knows any knitters who would bury a nearly-finished sweater at the bottom of their UFO pile for years rather than take the 45 minutes required to sew a few seams and weave in ends. (No judgment - we all have our quirks!)
But, here's the thing: the bigger you are, the less these really are advantages. Take #1. Yes, you can try on as you go. However, there is really no point to trying on your sweater-in-progress until you are closing in on the armpit. But by then you have already done a whole lotta knitting. And, if things (like gauge) have gone really off the rails, that's a whole lotta knitting to rip. (An aside here to say that every single top-down sweater I have knit has had to be ripped back to the beginning after reaching the armpit. Including BlueSand. Even after completing a generously sized swatch.) On a bottom-up sweater, I can start with a small piece, like a sleeve, work for several inches and then re-check gauge. Assuming the math is good, I can knit on with confidence. Much less of an investment of ripping has to happen.
Another disadvantage alluded to above is the length of the rows. Those last couple inches before the arms are split from the body are loooong rows. Not so bad for a knit row, but it takes steely reserve to launch into that much purling.
Yet another disadvantage is that you are working the entire sweater in one piece. If you save the arms for last, as most patterns do, that's a big mess of sweater twisting in your lap as you knit your sleeves in the round. Smarter knitters do the sleeves before the body, but then it's hard to double-check their length without the weight of the sweater body holding them in place.
Here's the thing about these last two points. The bigger you are, the longer the rows will be, and the more your sweater will weigh. So, as your sweater increases in size, all the disadvantages of top-down knitting are exaggerated. But, there's the biggest disadvantage of all . . .
No seams. Why is this a disadvantage? Seam give your garment structure and strength to carry its weight. Thanks to gravity, the weight of your sweater - both body and arms - is carried by your shoulders. In a bottom-up sweater, there are typically some nicely reinforced shoulder seams. (I give mine extra strength by constructing with a 3-needle bind off.) If you don't have seams, what is carrying all that weight? Your stitches. And, the bigger the sweater, the greater the weight and the greater the stress on those shoulder stitches. At the least the stitches will become distorted and throw off your carefully fitted and adjusted bodice, as well as the length. At worst the yarn will not be able to bear the tension and will break.
So, I know knitters don't love sewing seams, because if we did we'd be quilters. But, it's a trade-off that I am usually pretty happy to make because I know that it results in a more stable, stronger sweater. And the proportion of time spent sewing as compared to the time spent knitting is really a tiny fraction.
Have I convinced you?