I bought my hat to take with me to Hawaii in 2007. Its label claimed that it could be folded and packed without impact to its shape when worn. It turns out that this claim was absolutely true!
The hat is made of straw, is very light weight, and is so comfortable that I actually forget I'm wearing it. The brim of my hat is wide enough to keep the sun off of my face which is the important goal. When you get older, exposure to the sun not only causes wrinkles, but can leave spots on your skin as well. My dermatologist warned me against going outside (even in the winter time) without sunscreen or a hat. Add to that my eye doctor's orders to never go out in strong sunlight without eye protection, and you understand why when traveling to a climate like Hawaii's, makes it super important to follow Dr's orders.
There is just one small problem with my hat and that is that since it is so light, if it is a windy day, it will blow right off! The next time I go to Hawaii, I will buy a ribbon to thread through my hat and then use to tie it on.
I love that I can just throw it in my suitcase and use it as soon as I arrive, with no wrinkling or misshaping at all.