Modeling a hippy hoppy hat. The ´hippy hoppy hat´ is the name that Mexicans and Mayans use to describe this hat -- I admit to having no idea where they got this term. The hat is woven in humid caves from a material called sisal or henequen, a kind of agave, by Mayans. They weave underground because the high humidity allows the sisal to remain supple while the workers weave it. The hats, which are quite pricey, can be worn on formal occassions -- such as during a wedding -- or as a stylish street wear. The hats are said to repel mosquitos because of the odor of the sisal plant. Mexico is the second largest producer of henequen in the world, after Brazil.