By Liz McNeil, KnitChats Coach & Community Manager
Question: I am knitting a sweater in the round. Pattern says on selvedge edge knit first stitch and purl last. Do I need to do this in the round? (Yvonne)
Depends. Is the pattern originally in the round or is it done flat and you switched it to circular?
Selvedge edges are used for a couple reasons.
In flat knitting they help mark where you're going to seam things together. They make picking up stitches cleaner/easier but, more importantly, they provide structural stability. Seamed pieces can be heavy and, depending on the pattern, can have more delicate portions (i.e. lace). Where they aren't a continuous tube (like you get when you work in the round) they don't have the same built in stitch support of its neighboring stitch. Selvedge edges help compensate for that. Sometimes they do all that but also are there for a visual aspect. It might be noted in the informational portion of the pattern but if you aren't sure I suggest looking through the Ravelry gallery. It might be mentioned there.
In the round is a bit different. Selvedge edges are more the start and stop of where the sides of the front and back are. It helps create a visual marking since our brains like things to be clean, clear, and defined. It's sort of a way to add dimension and stylizing without having to get crazy. That delineation is most often noticed in cable work. It's not as much of a structural support thing in this case but it can be (once again, for things like lace or more delicate patterns). In all my years of knitting I have yet to see a pattern designer specify that.
If the pattern is knit flat but you converted it to the round that changes it up a bit more. Flat knitting patterns take into account those selvedge stitches. It's the whole "cast on x amount + x amount" portion of a pattern. When converting to the round you omit those + stitches. For example, if a pattern says to cast on 6 stitches +4 stitches you would only cast on those 6. Those extra 4 would add more to the overall size but might also throw off any patterning.
Long story short: no, you don't need to but you might want to. Swatch. Always swatch just in case. Circular swatches need to be done circularly or faux circular. If you go the faux route make sure to cut your floats and lay flat to block it. Always knit at least a 4x4 in swatch but sometimes a 6x6 in is needed.