I'll start with the most recent one: the CouCou Cable Chapeau.
It's worked in two layers. The outer layer is in 100% wool (worsted weight) (Wool of the Andes) and the inner layer is in a brushed alpaca nylon blend (Reverie).
The best part is that the pattern is available for free on the Knit Picks website!!!
I don't know how the model didn't melt wearing such a warm hat in the summer heat,
Photo Credit: knitpicks.com