The challenge was paper piecing. I think this fits into the challenge. I pieced six layers of card stock to create the shadow effect. I picked up this technique from Jennifer McGuire.
Here is the inside:
I love this little guy. All FSJ products. I experimented a little here, I just received my Journey watercolor pencils (Yeh!!) the oops fish on the front is on water color paper. The fish on the inside is on regular card stock. Both work well, but the watercolor paper blends better. I also used the ATS stamp Oops #AT-0206 and die (both you can get free for every $50 you spend.)