How can I create this "engraving style"?

[ClaudeFran]

Hi!

I am currently working on a logo; a leaping frog and I want to give it an engraving/authentic/rustic look. Something like this would be perfect.

http://4.bp.blogspot.com/-BNbMWI7Zf-U/U ... agrama.jpg

Fox have fur so it might easier to achieve than for a frog. But how could I give my frog's silhouette a similar texture with illustrator.

Cheers,

Claude.