Many people get different gauge when they knit than they do when they purl, because they do them at different tensions. Usually, if there is a difference, the purl tension is looser. When you knit a St st swatch flat, you alternate a row of knitting with a row of purling. When you knit a St st swatch in the round, you are always knitting. If you're one of those people who knits and purls at different tensions, your gauge in those swatches will differ.
This is also the reason that some people recommend the first stitch on a dpn should always be a knit stitch: there are enough tension issues at the end of needles that starting the next needle with a purl stitch will only cause more problems.
This is not universal: some people, either through luck or practice, knit and purl at the same gauge. If you aren't sure whether you do or not, though, the only thing to do is knit a gauge swatch and see, and in any case you should be aware that knitting flat and knitting in the round can have different gauges.
(From a post I made to the Socknitters mailing list on 4 October 2007.)
1 Comments
I think it was your post on socknitters back in 2007 that told me about the problem with my gauge: my purl tension IS looser than my knit tension... in fact, I just knit a hat for a friend recently using the Shaker Rib pattern "stitch" (using 4 or 5 rounds of purl followed by 4 or 5 rounds of knit until you have 3 or 4 "ribs" of purl... I'll post a photo of the hat after my friend gets it since I want her to see it before I post it! :))
To combat my loose purl gauge problem, when I purled, I bopped down to a needle 1 size smaller & it worked!
Cheers,
Jessica