feathers are light and fluffy and they behave badly when wet; whether they are wet with water or paint or cat spit (I rescued one feather from the cat next door - it was kind of ratty. I am studiously not-contemplating how that cat got that feather). However, other tests have shown that photos of feathers are very useful (Kate! take note!) and also violate no laws about owning bird feathers. So! win!
