A quick look at Ravelry, Payhip or any other pattern repository will reveal that seamless sweaters are hugely popular right now. But what are the advantages and what are you losing by not seaming?
The advantages are pretty clear, especially if you’re working a top-down sweater. You cast on at the neck, work to the bottom and cast off. You pick up around the arm and work to the cuff. Repeat for the second sleeve, weave in the ends and you’re done. You can try the garment on to check fit at just about any point in the process. There is no finishing required and it's almost instant gratification because you can wear the garment as soon as that last end is woven in. Compared with: cast on the back, work to the shoulders, bind off. Cast on the front, work to the shoulders, bind off. Make two arms. Sew them all together and then you likely still aren’t done because you probably have to pick up and add a neck or button band (or both).
So, if seamless sweaters are so great why do designers keep designing seamed garments?
There are two separate answers here, but they are related. The first is that seams have a function in a garment beyond the obvious ‘join the pieces together’. They are like bones and provide a framework to help the garment keep its shape. While not a big concern with heavy sweaters like Arans or Ganseys which, while traditionally seamless, are also traditionally knit at a much tighter gauge than a regular pullover, it is true that designs in finer yarns which are often worked at a looser gauge will often benefit from the structure and stability of a seam. An interesting and fairly recent development is what I call a hybrid-seamless sweater. This is when you cast on at the shoulders with a long tail or similar firm cast on (not a provisional), work the back and then pick up stitches from the cast on edge to work the front. The cast on stitches at the shoulder are quite firm and function much like a seam. (This technique is used in Reef by Libby Jonson. We have a sample if you'd like to see it.)
The second answer has to do with the use of superwash wools. This is because the treatment process makes the yarn slightly slippery and without that ability to grab onto the strands around it, the stitches slip. This is a great feature if you’re making a shawl and want that slinky drape but not so great when you want something with a definite shape.
It’s the combination of looser gauge and treated wools that leads to a garment being more prone to losing its shape – and benefiting from the stability of a seam.
A final observation about the preference for seamless garments is that increasingly, people don’t know how to sew by hand and so, quite simply, don’t know how to seam a sweater (full disclosure – I can seam a sweater fairly quickly but would be hard pressed to sew a shirt by hand). This is something people tell me all the time. They’ll say that they can knit/crochet just fine but never really learned how to sew up the finished product and are never happy with how the seams look so they opt to simply bypass the patterns which require seaming.
What do you think? Do you prefer seamless or seamed garments? Let us know in the comments.