One of our favorite sources of inspiration is the New York Public Library archives. They have an incredible digital anthology of hundreds of thousands of images from the library's collection.
We've recently been mooning over these beautiful prints from Photographs of British Algae: Cyanotype Impressions. The book was published in the mid 1800's when seaweed collecting was all the rage. Aren't the watery blues and delicate shapes amazing?
Here's a fascinating article, if you'd like to read more.