I finished the chemo hat for my sister-in-law. It started out like this, one skein of KP Shine Sport. I have used Shine Worsted for preemie caps and loved it because it makes such soft, comfy hats. SIL lives near Houston, though, and I was told that the temps there are still in the 100 degree range. So I wanted her hat to be lighter weight than the worsted preemie ones.
Unfortunately I didn't think about yardage. The assumption in the back of my mind was that one skein is ALWAYS enough for a hat. But at some point I happened to to look at the other hat I had made from this pattern on US#4 needles and saw that it had required 175 yards. (If you follow that Ravelry link you will see that it actually took 107 yards. Apparently I cannot read.) The Shine is 110 yd/skein. And the first hat was for a head that was 2" smaller in circumference.
So I ordered more Shine Sport. Two skeins, just in case my singleton skein turned out to be the last one of its dye lot.
Much finger tapping and checking of the mail box ensued.