I made this for a friend who is really into Celtic artwork and music. I had so many problems with this cake, but it was still fun to decorate. I know it's not 3D, but it's still Celtic. I used piping transfer for the design. Following the knotwork to color it properly proved to be a little more difficult than I thought, but it was definately worth it. After the photo was taken, I noticed some mistakes in the filling of the knotwork, and I corrected them. My friend loved it!