Knitting a Swatch - Is it necessary?
Ensuring you have the proper gauge (# of stitches & rows to match your pattern) will assure you that your project is the right size, has the right drape, and that you don't run out of yarn.
We recommend you knit a swatch with the recommended needles & measure with a swatch gauge. It is preferable for you to wash & block your swatch before measuring.
If you don't get gauge, use a smaller or larger needle and knit another swatch.