You will use all the skein of the solid color yarn.

I listed gauge but it is not as important since this is a cowl. If you feel that you are a very tight knitter then go up a size on all the needles. The same for if you are a very loose knitter, you can go down a needle size.

A long color way yarn like the Urth Uneek Fingering really works beautifully with this pattern but any fingering would be fine.