I use this one:
http://www.joann.com/joann/catalog/p...DID=xprd140434
They don't show the cutting end, but it's like a surgeon's lancet. I can get the smallest of stitches. BTW, I have a Janome and I feel 2.2 is too small for my eyes. I up it to 2.4 and 2.6 on items that aren't getting stress...