I/you/we/they stiffen. He/she/it stiffens.
I can give you several sentences.That leather will stiffen if you let it get wet.I felt him stiffen in shock as he saw the boss walk in unexpectedly.You can stiffen lace by adding starch.
Loosen up is the opposite of stiffen up.
I tried to find the answer to this question and was unable to. I did find out he used his hat for letters, bills, and papers instead of his pockets.
Letters, Bills, and Notes
You could make a hat out of almost anything. Common materials include wool (often felted) and straw.
cotton , fur, silk
Sports memorabilia hats are often created using many different materials. The most common materials are combinations of cotton and nylon. These materials allow for a hat that has a nice shape, while still allowing for some personalized fit when placed on the head.
75% Cotton, 25% Linen
It's a blend of cotton and linen.
The Grinch used the hair of his dog to make his coat hat. This made the coat hat extra insulated against the harsh winds and climate changes on his mountain and protected him better than a normal coat or hat.
The Grinch used the hair of his dog to make his coat hat. This made the coat hat extra insulated against the harsh winds and climate changes on his mountain and protected him better than a normal coat or hat.