I am simply amazed at how little has been written about curved needles (pricks) as knitting tools.
My first swatch with the first curved needles. There is some junk stitches, but the last 300 were very nice. And, since then, better pricks, have resulted in better knitting.
Mary Thomas, at least wrote briefly about knitting sheaths, and had pictures and drawings of knitting sheaths in her classic book on knitting. Certainly Mary Wright talks about knitting sheaths at length, and I even found a paragraph in one modern text explaining how to use a knitting sheath. However, there is even less on curved needles.
Curved needles can be used hand held to facilitate continental knitting. However, they come into their own when used with a long knitting sheath. The needle then pivots in the knitting sheath. The front leg of the stitch is used as at fulcrum to lever the yarn through the stitch. The effort comes from the large muscles of upper arm. Control and stability come from the knitting sheath and the inter–actions between the yarn, the fabric, and the needle. Therefore, the Yorkshire commercial knitting techniques do not work for all yarns and fabrics, but when they do work, they are very fast. This is a very different motion from any of the motions for using straight needles with knitting sheaths, and it certainly was not contemplated in the one modern text that describes how to use a knitting sheath.
The leverage available with a knitting sheath and curved needles is not as great as with a knitting sheath and straight needles, thus curved needles are not suitable for knitting very tight fabrics. Nor, are curved needles suitable for loose fabrics or lace. What we would call standard hand knitting (http://www.yarnstandards.com/weight.html) is too loose to use the fabric to stabilize the needle. However, I do not like those fabrics anyway. (And, I note, that the knit wool fabrics offered at good or fine clothing stores are also firmer than what results form following the recommendations of the Craft Yarn Council.) That is, professional or commercial quality knitting is firmer than the recommendations of the CYC.
However, if you want to knit a nice firm, consistent fabric very rapidly; pricks are your tool of choice. If you want to knit a fine Jersey in a day, get curved needles. If you want really consistent knitting, get curved needles.
So, she asks with a sneer, "Is it fun knitting that fast? How can you enjoy knitting that fast?" It is like riding in a car. In a new BMW, it is comfortable going 80 mph. An old Ford Model T is not comfortable at 50 mph. NO! with most needles, it would not be any fun knitting that fast, but with curved needles, when you get everything dialed in, it is just knitting at the natual speed that feels right.
I have some Special Blauband sock wool, and I have not yet figured out how to knit it with curved needles. It is on 2.4 mm pricks and I was lucky to get a thousand stitches done in 4 hours. I mean I was struggling to do 5 spm, so I do not have this all figured out yet.