Frans Hals, Portrait of a Young Man, 1638-40
Beaver hats were very expensive and often helped to denote status. A fine beaver hat would likely have cost as much as a week's wages for a tradesman or silversmith, so they were a highly prized possession.
For further reading on Beaver Hats please see:
http://en.wikipedia.org/wiki/Beaver_hat
Making a beaver hat step by step:
http://www.google.com/imgres?imgurl=http://people.ucsc.edu/~kfeinste/hi…
105%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26ndsp%3D21%26tbs%3Disch:1
Another example of the beaver felting process:
http://cwh.ucsc.edu/feinstein/The%20process%20of%20felting%20a%20Beaver%20Hat.html