Worked like a charm. Water just beads on my hat now...
I applied this to my 2 Ultrafino straw hats and the product went only evenly and when it dried, it was impossible to tell it was there. Haven't tested it in the rain yet, but I see no reason why it would not be effective.
I love love love this hat! Beautifully made and a perfect fit. It took em a while, but definitely well worth the wait. Best hat I've ever owned b