I am following a most wonderful blog: "Altered book lover".klick here
And you will find it under Thursday, May 3 2012.
She has a post how to pound flowers for coloring paper or fabric.
Now that is so interesting that I tried it with young fern from around our house in the Vosges.
I like it although the result is not quite satisfying. I will go on experimenting.
The blue color is coming from "Lichtnelke" (Silene dioica) the color of which is actually rather pink.
There are no larger flowers at the moment to experiment - bigger would be better.
You put the petals inbetween two sheets of paper and then with a hammer......!!!
But read more at Altered Book Lover's page