I've been knitting swatches with my handspun. I thought I'd share 2 hints with you on how to choose the appropriate needle size. (btw this also works for commercially bought yarn where the ballband has gone awol)
1. A quick method (preferably requires a needle gauge) - Double the yarn, gently twist it together to simulate a 2 ply. Choose a needle that's the same thickness as the doubled yarn. I usually use a needle gauge to judge the thickness of the yarn. If the yarn is a little variable in diameter then take and average of the thickest and thinnest parts. If in doubt err on the bigger needle size.
2. Use a ruler or wpi tool to measure the average number of wraps per inch of yarn. Then use the table below to figure out the needle size. This works well for simple plain yarns but not so well for crazy fluffy ones with added feathers or beads. Thistable is a little different from those published elsewhere as this is tried and tested for semi-even handspun.
Yarn weight wpi needle size
Laceweight 18 or more 2-2.75mm
4ply/Fingering Weight 16 2.5-3.5mm
Double knit 14 3.5-4.5mm
Aran 12 4.5-5.5mm
Chunky 10 5.5-8mm
Super Chunky 8 or less 8-15mm
Last night was our T'chai Ovna knitters night. Vonnie and I were joined by Angelabdc from ravelry and had a fab time.