Skewed knitting

Is there a formula to determine if a singles yarn is going to cause my knitting stitches to be skewed after washing?

In my humble opinion, the biasing that occurs with knitting, singles yarns, can't be put into a simple formula. There are several factors involved, particularly the inherent body - the resistance to being twisted - that varies from fiber to fiber. Then you need to also consider the knitting stitch that you are using.

A very simple check of any particular yarn plying back on itself, as it is being spun, may give you the answer. If you stop spinning and let the singles yarn ply back on itself, and it does so with good definition, then it needs to be a plied yarn to avoid skewing or biasing in stockinette knitting. Since that particular singles yarn has the ability to ply back on itself, in all likelyhood, it will be able to twist the knitting stitches, especially each time it is wet for washing.

Conversely, if you stop spinning and let the singles yarn ply back on itself, and the plies become soft with poor definition, it will probably not skew in stockinette knitting, because there isn't enough twist and body to push the stiches around.

In my experiments using smaller, needles and a tighter guage, will give the singles yarn less room to move, bias or skew a stockinette stitch. A rib stich or lace yarn overs also reduce a yarns ability to skew.

A few of the other factors that I have noted in my spinning, besides body, have to do with the length of the fiber, the amount of fibers held together and the arrangement - parallel or haphazard. (http://groups.yahoo.com/group/TechSpin/message/3771 July 14, 2001.)